Betrayal and lies were two things that Derek could not tolerate. Trust was something he valued above all else, and when he felt that someone was betraying one of his principles, his natural instinct was to flee. To distance himself to endure that wound in solitude.

The day he found his wife and his best friend together in his bed, his despair and disappointment were so great that he fled aimlessly. He did not even bother to pack a suitcase or think about his next destination. He simply took the keys to his car, tucked his documents into the inner pocket of his coat, and walked out through the front door of his home in New York, making the greatest effort not to look or listen to his wife, who begged him to stay amidst tears. But he could not stay.

He sat in the driver's seat, started the vehicle, and began to drive away. He drove for hours, so focused on the road and the storm that he did not realize how far he had gone until he stopped on the opposite coast of the country.

The betrayal had been twofold. On one hand, was his best friend, practically his brother, whom he had known since they were young children and had made a part of his family. The one who had been with him from the first day of elementary school to the last day of surgical residency at the hospital in New York. Going through all kinds of moments in between, like the births of his sisters, Mark's parents' divorce, Christopher's death, summer camps, baseball games, toy car races, mischievous pranks on his sisters, first days of college, study afternoons, among several unforgettable moments. He had been his companion since he could remember.

And on the other hand, his wife. The person who made him discover what it was to love at inexplicable levels by science. The person he trusted with his eyes closed. The person who knew him the most in the world and didn't need words to know what he was thinking. The love of his life. His best friend, his partner in crime, his soulmate, his other half, his road companion, the first person he saw when he woke up and the last when his eyes closed. The leading actress in his dreams. The doctor who had taken his last name. The She-Shepherd, the best surgeon he knew, his ally in the operating room. His pillar and his support. His home and his shelter. His refuge. Addison had been all that and much more to him.

And to have seen her that night, naked with another man, doing something that only she should have done with him, kissing him as she used to kiss him, pulling his hair as she used to pull his, was... devastating. It was shocking, it was exasperating, it was disgusting, it was painful, it was sad, in simple words, it was the worst thing that had ever happened to him in his life. And the only possible solution –if there was one– was to flee.

He fled from the two of them as far as he could that night. He bought a trailer and a plot of land in the forest to start his new life in Seattle. He accepted an important position in the neurosurgery department that Richard, one of his mentors, had offered him in one of the most prestigious hospitals in the region. He met Meredith in a bar, quickly fell in love with her, and felt that he had finally rebuilt his life. But his escape plan had not worked entirely, because a few months later, Addison came after him.

When she arrived in Seattle and handed him the divorce papers, Derek refused to sign them and decided to give his marriage a second chance. He wanted to bet once again on the love they once had so strongly. He wanted to bet on his little family. He wanted to believe that all those years together had not been in vain and that the feeling that had united them for the first time was still there, hidden somewhere waiting to be found. He wanted to forgive her and try again, but... unconsciously he couldn't do it.

The pride, resentment, and disappointment that still lingered within him never allowed him to truly forgive his wife. That, along with a lack of communication, indifference, betrayal, and lies on both sides, had led to the end of their marriage.

However, Addison was not the only one who had betrayed him and made him flee disappointed. Meredith didn't need to sleep with his best friend to break all the trust he had in her when she sabotaged his clinical trial on Alzheimer's.

He had worked hard on that trial for several months, hoping to improve the lives of millions of people affected by that incurable disease, but above all, he was working to help her. Since Meredith found out she carried the APOE ɛ4 gene, those fears and concerns about the possibility of developing Alzheimer's in the future became real, and Derek had vowed to try everything possible to help her if that happened.

But apparently, she didn't care about her own life, the lives of millions of people, or the million-dollar funding from the FDA. She altered the results by giving Adele Webber an active drug instead of the placebo she was supposed to receive, thus corrupting all the results.

She had sworn to him that she had only done it once, but... could he believe her after all?

She had looked him in the eyes every day, slept by his side every night, and continued working on the clinical trial as if nothing had happened. As if she hadn't condemned the lives of a hundred other people in an attempt to save that of an acquaintance.

And yet, Meredith didn't seem to care about the cancellation of the clinical trial and the funding loss, nor the people who died in the process, nor the lawsuit the hospital would face because of it. She didn't care that Derek had been blacklisted by the FDA. She didn't even care about losing her job, let alone the possibility of going to prison. How could he stay with a person who not only ruined everything but showed no remorse? Someone who didn't take responsibility for their actions. Someone who didn't know the difference between right and wrong.

That day he felt a double betrayal again. By Meredith, whom he believed was the ultimate love of his life and would never lie to him in such a serious way about people's health; and by Richard, whom he considered a friend and an ethical professional, and who nevertheless did everything possible to cover up and minimize the situation, taking all the blame and lying to the medical board for her.

That night he fled again. He packed all his belongings, stored them in two large suitcases, and left Meredith's house without notice. He needed to get away from her. He needed some space alone to process everything that had happened.

He had ended up at Mark's apartment, who had offered to host him as soon as he heard the news. Since then, Derek had been living there with him –and sometimes with Sofia, his friend's six-month-old baby.

Two days ago, while getting ready to go to the hospital, his cell phone rang. The caller ID showed his younger sister's contact, and without a second thought, he had taken the device and held it to his ear.

"Amy? What's wrong?" he had asked, concerned. Getting calls from her early in the morning was not an everyday thing.

"Bizzy died last night, Derek."

"Bizzy?"

"Addison's mother."

"Yes, I know... God. I'm so sorry. Do you know what happened?"

"I don't know much, I think it was an aneurysm... I haven't been able to talk to Addie yet. She's traveling to Connecticut and..."

"When is the funeral?"

"Tomorrow morning. I'll travel with some colleagues from my practice to accompany her. I've already booked the tickets and the stay in a nearby hotel. I requested a double room in case you wanted..."

"Yes. I'll go to the airport right away. See you later," he had said before ending the call.

"Are you going on a trip?" Mark had asked, approaching with a toothbrush in his mouth. He had overheard the last part of the call.

"Addison's mother died last night."

"Oh, man... I'm sorry. She must be devastated."

"I have to go to Connecticut. I'll send Richard an email on the way to explain. Now I have to pack my bags."

"Send my condolences."

Derek nodded and quickly rushed to pack an improvised suitcase.

He had packed a black suit, a couple of shirts, shorts, a pajama shirt, and two sets of underwear. Few things that would fit in the carry-on suitcase, he wasn't going on vacation, he was going to a funeral. A funeral where he knew there would be mourning activities with his ex-in-laws suffering.

He knew what he was getting into when he decided to go... but he never would've imagined that he would kiss Addison in Connecticut and that, from that moment on, he wouldn't be able to think of anything else but doing it again.

After drinking a few sips of Scotch whiskey and quickly climbing the stairs to the room in a strange kind of discussion-confession, Derek found himself on top of her, kissing her again, with one hand resting on the mattress supporting his weight, while his other hand –in a very unsubtle way– unzipped the black dress she had worn to her mother's burial that same morning.

That dress also had a round neckline, but it was nothing like the one she had worn the day she received him at her house. That one –in addition to highlighting her slender figure and long legs– had a neckline so wide and pronounced that it barely left the bra straps of Addison peeking out on the sides. Yes, his gaze had inevitably drifted a few times toward the area below her pearl necklace. He even felt sorry for looking at her like that given the situation, but she was incredibly beautiful. Not that he expected to see her disheveled and poorly dressed, just that... he definitely did not expect to see her looking that good.

The little he had managed to see with his fleeting glances had been black straps, adorned with intricate patterns that looked more like a work of art than an intimate garment. Typical Addison. She always cared about buying the most expensive and elegant lingerie. And there was a time when he deeply appreciated her for doing so.

Once Derek finished sliding the dress down her legs, he moved a few inches away from her mouth to observe her body exposed. He couldn't help but let out a small laugh when he saw that she was indeed wearing a black lace bra compressing her delicate round breasts, just as he had imagined.

Addison arched her back as soon as she felt his hand brushing against her skin, giving him greater access to unfasten the hooks of the bra. He quickly slid the straps down her arms and got rid of the garment, leaving her breasts exposed.

Oh, he had no words to describe how perfect Addison's breasts were. Well, maybe that was the word: perfect. They were soft and delicate, perfectly rounded, but adorable. They were the exact size of his hand. So she was not surprised when he cupped his free hand to touch her. With the tips of his fingers, he made small movements, gently exploring each protrusion and fold. She closed her eyes, surrendering completely to his caresses.

Derek's lips sought Addison's erect nipples and kissed them carefully. His warm tongue traced circles around them, eliciting soft moans that drove him crazy. She crossed one of her legs over his hip, pulling him a little closer to her as she tugged on his little waves. Feeling the friction of their bodies had caused physiological effects in her ex-husband's body.

"Just do it," she said in a murmur that seemed like a mix between a plea and a command. But he couldn't hold back any longer.

So Derek, without saying a word, straightened up and unbuttoned his own pants, releasing his hardened member that yearned to enter the warmth of Addison. He slid her panties down her legs and with a gentle but firm gesture, he took hold of her hips and plunged inside her, causing her to release a muffled moan of pleasure.

Addison clung to him tightly, as if afraid that at any moment everything would disappear and leave her plunged into the darkness of loneliness. She felt her body arching with satisfaction. Her legs enveloped him as her hands roamed Derek's back in a desperate attempt to keep him by her side forever.

Being with him felt like a dream she didn't want to wake up from. Each thrust took her to a place where only pleasure existed, where the outside world disappeared and only the two of them remained, united in a whirlwind of intense and delirious sensations. Once again, Addison .

Derek looked at her with an overwhelming intensity, his eyes burning with unrestrained passion, his mouth curved in a sensual smile that made her tremble. She wondered if she was the reason for that smile, or if he was simply using her as a distraction from his daily problems. But she couldn't blame him, because she was using him in the same way.

Being with him silenced her thoughts. It made her stop thinking about her boyfriend who hadn't traveled to Connecticut, who hadn't called her all day, or the guilt she felt for cheating on him. She didn't think about her mother's sudden death and the surreal days she had been living since then.

Of course, she was aware that the guilt would come back and be stronger than the first time, but at that moment she decided to stay there, in the warmth of his body, enjoying what he offered her.

Derek moved closer and took Addison's legs, placing them over his shoulders to achieve a deeper penetration angle. He passed both hands underneath her and embraced her, holding her even closer to him as he increased the pace and intensity of his movements. She bit her lower lip smiling, knowing that when he did that, she wouldn't be long in reaching her climax.

Their bodies fit together perfectly as if they were two pieces created solely to work together. Addison clung to the sheets tightly as he kissed her neck desperately. Her nails left marks on the white fabric as she let herself be carried away by the ecstasy that took over her entire being. Oh, she truly felt like she could explode at any moment if he continued moving his hips that way.

"Oh, God!" a muffled cry finally escaped her lips as she felt her pelvic muscles contracting. "Oh, God..."

Derek could feel the pressure of her walls and followed almost immediately, reaching his own climax and spilling inside her with a last sigh of shared pleasure.

He slowly began to move away from her, and he lay back on his side, as their heartbeats tried to return to normal.

"Did we just...?" Addison asked with labored breath and the sound of blood still pumping in her ears. She wasn't looking at him.

"Yes."

And then silence filled the room.

~•~

Addison began to wake up as soon as she felt the first rays of sun seeping through the blinds. She didn't feel very well, she had a throbbing headache, some nausea, and a dry mouth.

As her vision cleared, she could identify the vibrant burgundy color of the walls of her childhood room, but something was not right. No. Her pillow, where she had her head resting, was slowly moving up and down, as if it had a life of its own.

It was then that she turned her head in fear and realized that she was actually resting on her ex-husband's bare chest. Surprise invaded her and she remained still for a moment, trying to remember how she had ended up there. Slowly, the pieces began to fit together in her hungover mind.

She and Derek had returned from the tea house and had a few drinks in the living room, for some reason she had gotten upset with him and had gone upstairs, but he had followed her. After that, they argued... was it an argument or just a conversation? What were they talking about? Why was she upset? She remembers yelling, but... she also remembers being silenced abruptly by Derek's mouth. And with a little more effort, she could visualize some fleeting images of him on top of her, undressing her and kissing her bare body...

She looked at her own body covered by sheets. She was naked just like him, and that could only mean one thing: they had had sex the night before and eventually fell asleep. They had slept together.

And she had really slept very well by his side because it was the first night she could truly rest since all the turmoil started with Bizzy in Los Angeles, Susan's surgery, the wedding, the deaths, the funeral, her family, her father, her brother, Derek, Sam... and all that kept her up at night.

Addison slowly sat up in bed, trying not to wake Derek. However, the moment she moved, she felt his arms gently wrapping around her, pulling her back to his chest. The warmth of his body felt comforting and familiar. Despite everything they had been through together, there still existed a deep connection between them that not even time had managed to break: muscle memory.

She was always intrigued by the concept of muscle memory. This is based on the brain's ability to store movement patterns in motor memory. This information is stored in the cerebellum, the part of the brain responsible for coordinating and regulating body movements. As a movement is repeated, the brain memorizes it, whether it's the steps of a dance choreography, the order of chords on an instrument, movements while playing a sport... or sleeping while embracing a person.

Addison had always liked to sleep hugging Derek, especially on the harsh winter nights in New York. She used to spoon him. She would rest her head on Derek's shoulder, throw a leg over his body, and hug him with both hands.

Although she also loved being hugged by him. The simple act of him wrapping his arms around her body transmitted a peaceful sensation that allowed her to fall asleep quickly. She felt protected in his embrace. She felt safe.

During the golden days of their marriage, they did it daily. And thanks to that repetition of actions, their brains created neural connections that strengthened their muscle memory, making it more resistant to forgetfulness. Even after six years of divorce, where those types of hugs were not very appropriate.

Addison carefully lifted Derek's arm that wrapped around her and moved away from him. This small movement made him open his eyes and stare at her with a confused expression. She didn't seem to be the only one disoriented there. Had they drunk so much last night?

"It's not that I look bad naked," she said, attempting to break the tension with a joke.

"What time is it?" he whispered, not responding to what she had said. She didn't know if he hadn't heard her or if he was already regretting what they had done.

Addison turned to look at the alarm clock on her bedside table.

"It's eight in the morning."

"I'll have to leave in a few hours. My flight leaves at four in the afternoon."

Was that really all he was going to say? Was he not even surprised to wake up naked next to her? Or did he really not remember anything from the night before? What the hell had they drunk last night? Had Archer tampered with that whiskey bottle?

She usually had a high alcohol tolerance inherited from her beloved family. She never used to experience hangover symptoms the next day, but now... did she maybe overdo it with the Scotch? And Derek too? Or maybe it was the accumulated fatigue that was starting to take effect?

"You don't look bad naked," he said with a smile. So he had heard her after all.

"You shouldn't have seen me naked."

"It wasn't the first time," he shrugged.

"Derek, what did we do? Why did we do this? Oh my god... This shouldn't have happened," her voice began to fill with anguish.

"It's not as bad as it seems," he said, trying to caress her naked arm, but she pulled his hand away.

"Of course it is! We are cheaters!"

"We already were before doing it."

"You don't even care that you cheated on Meredith?" she looked at him indignantly. Was this how he had acted when he cheated on her?

"Meredith and I are not together. I told you last night."

"Are you serious, Derek?"

"Yes. We broke up a month ago. I'm living with Mark..."

"Is it a real breakup or is it like the one they had when I returned to Seattle for the first time? That time you were with a nurse... Rose?"

"It's different. This time it's definitive. I guess..."

"May I ask why?" she said, with a thread of voice. She shouldn't even be asking that, but she needed to know.

"It was... it was a combination of things, you know? I could say it was just because of a work problem, but... it wasn't just that. She and I are not on the same page."

"Because she's twelve?"

"She's not twelve," he laughed.

"Right, she must be like... seventeen? Eighteen?"

"When you're a doctor, you're supposed to have a certain sense of morality. You have an ethical obligation. We made an oath where we promised to do everything possible to help people... regardless of their sex, age, nationality, occupation, religion, or the relationship we had with them. Isn't that so?"

"Yeah..."

"We don't have the right to prioritize one person's life over another just because they're close to us. Or because they're a family member, friend, or acquaintance. We can't choose for our convenience. And that sometimes brings helplessness, pain, anger... but... it's what is right. To treat and heal all people depending on their health condition, and not on the bond that unites us. Meredith doesn't understand that."

"It's hard to understand, Derek. As a doctor... I'd also try to do everything possible to save someone I care about. In fact... with Susan and Bizzy... maybe I did more than I should have. Maybe I treated them especially just because they were family."

"It's not the same. You didn't compromise other people's lives to save your loved one."

"No, but..."

"I'm not allowed to talk about this with third parties because the hospital could be sued, but... she did something very wrong, Addison. Very wrong."

"Okay..."

"She... she screwed up the lives of millions of people just to benefit one. She screwed up my clinical trial, the hundred patients who were involved, the FDA funding... in many things."

"I understand."

"And you know what's worst? She doesn't even care. And she said she'd do it again. She doesn't think what she did was wrong or incorrect. She doesn't regret it and... I can't be with a person who can't differentiate between right and wrong."

"Oh..."

"So I ended things with her. We never legally married, so I'm single again. I'm living with Mark."

"I'm sorry..."

"It's okay. I'm okay like this..."

"Listen, Derek... I need to be honest with you and..."

"Is this the moment you tell me you're not looking for a serious relationship because you live in Los Angeles and the nights there are drugs, alcohol, and commitment-free sex?"

"God, where do you think I live?" she laughed, shaking her head.

"Well... with Amelia."

"Oh, she doesn't frequent those kinds of places. She's already a responsible adult."

"I can't believe that after so many years, you're the one who ended up living with Amelia... I'm sorry."

"It's not as bad as it seems. She no longer leaves beer cans lying around the kitchen, nor does she sneak out the window to go to nightclubs on weekends. And she bathes quite frequently, without me having to force her."

"God, do you remember that stage? Why don't teenagers like to bathe?"

"I remember when you poured a bucket of cold water on her in the garden..."

"Oh, that wasn't to bathe her. It was because she had a hangover and smelled of vomit."

Addison laughed recalling that day. Amelia was 16 or 17 years old and they were visiting Carolyn's house. It was summer and classes were about to start when she sneaked out to a party the night before. Derek was very angry with his sister that day.

"I'm glad she bathes now..." he said with a small smile.

"I adore Amelia... she will always be my little sister..."

"I guess I never told you, but... thank you, Addie."

"For living with Amelia?" she said raising an eyebrow.

"Yeah, well," he laughed, "but I mean... for loving my family as if it were yours. For loving my sisters, for loving my nephews and nieces, for always caring about them... they still ask about you."

"I know... I talk to the older ones on Facebook. They love me more than you."

"It was always like that."

She forced a smile. Why was he telling her this now? Just because he had broken up with Meredith and realized what he had lost with her? Why do they always realize so late?

Addison's cell phone suddenly rang, interrupting her conversation, and she turned to take the device in her hands. Her face quickly transformed upon seeing who was on the other end of the line.

"Sam?" Derek asked, raising an eyebrow in surprise.

Addison felt a chill run down her spine and her skin quickly prickled. Chatting with Derek had completely made her forget about her boyfriend.

She remained motionless as the sound of the cell phone continued to ring. She could swear it was getting louder each time.

"Aren't you going to answer?"

"Not right now... I'm talking to you..."

"I have no problem with you answering, maybe it's something about work... a patient, right?"

"Don't think so..."

"Answer," he said, getting up from the bed to search for his clothes. All his clothes were scattered in a very messy way on the bedroom floor.

Addison took a deep breath and brought the device to her ear to answer.

"Hi," she said in a very nervous tone, hoping Derek wouldn't say anything from behind. She hadn't told Sam that he was there either.

"Hey, baby. I was gonna call you last night but my battery died," Sam said from the other end of the line.

"It's okay..." Addison responded while watching Derek dress in front of her. Modesty was not something that existed between them, not after the thousands of times they had undressed each other.

"How are you?"

"Fine..."

"How was Bizzy's funeral?"

"Fine..."

"Are you coming back?"

"In a few days. I have to take care of some paperwork still. Legal matters, inheritance, donations, lawyers... you know. Those things."

"Do you want me to come over there? My patient got out of the ICU a few hours ago."

"No, it's not necessary for you to come. I'm fine."

Sam seemed to notice the tension in her voice. The call became even more uncomfortable, and Addison felt the pressure mounting. She knew that sooner or later she would have to face the consequences of not being honest with her boyfriend. But clearly, that moment would not be now.

"Are you sure, baby? I don't know if it's the phone line but your voice sounds a bit strange. Are you crying? Do you really not want me to come?"

"Yes, I'm serious. You don't need to come, I'm fine. We'll talk at home."

Derek turned his head and looked at her confused. Addison talking to Sam at her house? Since when were they that close? Why was he insisting on coming now when the funeral had already passed?

"Addison, you know at some point you'll have to stop pretending disinterest and talk about what happened with Bizzy," said Sam, annoyed. He felt she was avoiding him again like she did the night she returned from the hotel. As much as he tried to be understanding with her, his patience had its limits.

"I can't talk right now. Okay? I'll call you later. Goodbye."

And without waiting to hear his response, Addison ended the call. Derek continued to stare at her as if he was waiting for an explanation from her.

"I'm sorry, I... ahem," she could feel a knot forming in her throat. The anguish. The guilt. The lies. The betrayal. Everything was building up inside her.

"You and...?"

"Sam and I are together," she said quickly, looking away. She didn't want to see Derek's face change from confusion to anger. She knew he would be angry, lately, everyone who found out about their relationship reacted that way.

"Wait a moment, am I hearing correctly? You and Sam are together? Together as a couple?"

"Yes..."

"I can't believe it. You're incredible, Addison. When did you think it was a good idea to sleep with your best friend's ex-husband?"

"It's not how you think, he was..."

"He was there? Is that what you're going to say? Did you sleep with him just because he was there? Wow, if you're going to sleep with our whole group of med school friends you could at least come up with a new excuse. Who's next? Naomi? Or have you already slept with her?"

"Okay, enough, Derek. I understand your anger, but you have no right to claim anything from me. We stopped being a couple several years ago."

"Yes, because you cheated on me! Just like you just cheated on Sam. Maybe this works as a vicious cycle and tomorrow you'll sleep with Mark Sloan again. Oh wait, didn't Sam have a best friend who played basketball?"

"Stop insinuating that I'm a whore!" she shouted, holding onto the sheets covering her body tighter.

"And are you not? You slept with the three men from our group. Congratulations, a new record!"

"Can you stop insulting me in my own room, in my own house? If I slept with three, four, or forty men it's none of your business. It isn't. We got divorced. Do you understand that? Divorce. It means you can't claim anything from me. Especially not for what I do after divorcing you."

"Did you do this out of revenge? Out of spite? To keep bothering me?"

"Of course not! Do you think I'm dating him to make you jealous? Don't be ridiculous! I haven't thought about you in years."

"Yes, and it seems about Naomi neither. What does she think about you sleeping with her ex-husband? Is she happy?"

"Sam and I are in love."

"And that's why you cheated on him with me? Oh, wait, he couldn't travel for work and I was here. Isn't that the story?"

"Why is it so hard for you to understand that we are in love? Isn't that the excuse you used when you met Meredith? Weren't you in love with her like never before? Why couldn't the same thing have happened to me with Sam?"

"Because your relationship doesn't make sense!"

"And yours with the twelve-year-old intern does? Oh, wait. That relationship is fine 'cause when you were in university she was learning to read and couldn't hang out with your group of friends!"

"Yes, you know what? She didn't sleep with all my group of friends!"

"Then why don't you go back to her? Why did you come here in the first place?"

"Out of respect!"

"Oh, wow. What a way to show respect, sleeping with me when my mother died. That's what you did, you took advantage of my vulnerability to have sex with me because you don't know how to be alone! You fought with Meredith and came running to me because you can't be alone!"

"I thought you were single!"

"Would that have changed the situation? You used me so you wouldn't feel alone! You can't stand yourself. You hate yourself so much that you need someone to make you feel good about yourself! That's why you came! Because the only one who could sleep with you is your stupid ex-wife who chased you to exhaustion and you still rejected her."

"You're right, with you, you always have easy sex, if you don't even make an effort to close your legs!" he shouted angrily.

"Can you leave my house now?" she shouted in the same tone of voice as him.

"That's what I want the most! I want to leave and never see you again in my life!"

"Same here!"

"Whore!"

Derek finally spat out that word with a fury that he had avoided saying throughout the argument, grabbed his things, and left the room, slamming the door loudly.

And so, Addison was left alone in the room, feeling small and unprotected. Surrounded by a sea of tears and desperate pain, feeling the frantic beating of her broken heart as the tears continued to flow uncontrollably.

She regretted more than ever everything she had done in the past few days. She felt that she deserved everything Derek had said to her because it was true. She wasn't the victim in this story, not with Sam.

She felt like her whole world had ended right there...

But that was just the beginning of the end.