A/N: Thank you for all the amazing reviews on the first chapter – so heartening to see everyone's interest. And all the alerts as well – thanks so much guys. So on with the chapter.

Standing at the nurse's counter, Callie scrawls notes on a patient's chart as she tunes out the hustle and bustle of the hospital around her. Since last night's surprising development with Piper, Callie had been avoiding Mark to escape the cold hard reality of the situation – she had become someone's mistress. Callie really didn't want to see Mark's smug face when she is forced to admit that the statement of no one gets hurt in the relationship had been so very, very wrong. It's not often that Callie is forced to eat her words and she really wished this wasn't the reason she had to.

After leaving Piper's apartment, Callie had suffered from a very restless night as her moral compass berated her for her actions. Words can't convey how guilty Callie felt about being the "other woman" in a relationship. All Callie can see in her mind is the pain radiating out of those brilliant blue eyes – and Callie will never be able to forgive herself for causing that hurt to an innocent victim. Even if Piper's relationship was on the rocks, no one deserves to be treated in such a callous way.

Although violence is never the answer, Mark may earn himself a chart in the face if he starts on with one of his lectures of the poor morals of Callie's life choices. Glancing up, it looks as if Mark's face has already come in contact with a wayward chart judging by his battered appearance. Suddenly, Callie's morning is looking slightly brighter as she's not the only one whose life has taking a turn for the worse. Once Mark gets close enough, Callie asks as she tries and fails to hide her cheerfulness, "What is wrong with your face? It's all mushed up and weepy."

Mark gingerly touches his face as he replies, "I took the superb advice you offered me last night about telling Derek about Lexie and I. I now have intimate knowledge of his right hook as Derek's reaction was as I had expected – physical."

"I'm sorry, but you did catch him at a bad time." Callie replies as she lays a comforting hand on the pouting surgeon's shoulder. The gossip mill had already spread the story of Derek being accused of murder after his radical operation technique on a patient.

"Boo hoo, we've all lost patients. But we're men and that doesn't give him to act like some frat boy. But I know what will make me feel better." Mark says as a lecherous grin spreads over his face. "Give me all the intimate details of your little rendezvous with Longstockings."

"Her name is Piper. I'm not dating Pippi Longstockings. And the fact that she's a children's character makes this slightly creepy," Callie growls, even though she know Mark gets the name wrong to illustrate his point on Callie's lifestyle choices. Since Mark became the shining example of a monogamous relationship, he has been unbearably vocal about Callie's private life.

"Whatever, the name isn't important," Mark continues with. "With a name like Piper, I would imagine that she's quite flexible. It's heading towards a stripper name. So details, Torres."

"It was fine. Definitely got the adrenaline coursing and blood pumping," Callie says as she brushes off Mark's question and pretends to be interested in the chart. Mark's ears prick up at this deflection and he decides to prod a little deeper.

"And…" Mark asks, causing Callie to huff in exasperation. Mark is like a small, immature child who wants candy or in this case, details of Callie's sex life.

"Well, it was fine until her fiancée came home and caught us in bed," Callie says under her breathe, even though she intends for Mark to hear. Mark's face adopts a comical expression of surprise before letting out a bark of laughter. Clapping his hands over his mouth, Mark attempts to hold him a snort as Callie picks up her chart and hits him on the shoulder.

"It's not funny Mark, I feel terrible. I use to that person at the end of the bed," Callie says with several hits to Mark's body. "I was the jilted lover who had unrequited love for my entire marriage because my husband pined after his best friend. I know how it feels and I wouldn't wish that on anyone else," Callie says as her voice hitches slightly as her gut clenches as the feeling of guilt consumes her body.

Seeing the remorse etched on Callie's face, Mark lays a comforting hand on her shoulder. "It's not your fault. You have nothing to feel guilty about because you didn't know that the fiancée existed. Did you?" Mark questions.

"No, the first I knew of her was when she stood at the foot of the bed. But I never exactly asked either. It wasn't like I was on top of her and asking about her relationship status," Callie responds.

"So you're a topper," Mark comments earning himself a withering look from Callie. "This isn't your weight to bear, Torres. It's not your fault as you didn't know. You didn't cheat. You need to let it go." At Mark's logic, Callie lets out a noncommittal grunt as she avoids his look of concern. Being the other woman in a relationship had just confirmed Callie's long held view that relationships are things of fairy tales. "Callie, don't beat yourself up about this," Mark pleads, not wanting his best friend to sink even deeper into the dark side of non-relationships. If Callie doesn't improve soon, Mark is going to get Bailey to organise an intervention as if Christina Yang can sustain a relationship – anyone can.

Staring down the corridor but not really looking, Callie ponders Mark's statement. Logically, Mark is right – Piper is the one that cheated and therefore the one at fault. But that does nothing to remove the crippling feeling of guilt as Callie was the other woman and she feels equally responsible. From experience, Callie knows that infidelity in a relationship is the kick in the guts that someone will never truly recovers from.

Musing to herself, Callie decides that celibacy is becoming an increasingly attractive life choice. But then a face down the hall throws Callie out of her analysis and puts her in a tail spin. Frantically pulling Mark in front of her, Callie glances around his body at the person she was adamant she would never see again.

"What are you doing?" Mark question as he is manhandled by Callie until he is standing awkwardly in front of her.

"Shhhh, she'll hear," Callie responds as she covers Mark's mouth with her hand. Double checking, Callie's worst fears are confirmed as that woman approaching from down the corridor is the fiancée – Arizona. Callie would recognise those brilliant blue anywhere. "That's her. The blonde approaching. She's the fiancée," Callie adds causing Mark to spastically twist his head around to catch a glimpse. "Try not to make it so obvious." Callie growls out as she too keeps her eyes trained on the woman.

The two surgeons watch as the blonde turns the corner and disappear from view. "Someone cheated on her?" Mark asks in a disbelieving voice. "Is Piper blind?"

"What? Of all the problems and issues that arise from that woman wearing the dark blue scrubs of an attending, your concern is how someone could cheat on her? She works here, Marcus Sloan, here!" Callie replies as panic creeps into her voice.

"Ahh… she's hot," Mark stutters out as Callie disintegrates into a crazy lady.

"The fiancée works here, Mark. I work with sharp implements. I'm dead. I'll have to start wearing Kevlar to work," Callie wails out. When George had cheated with Stevens, Callie had vividly imagined how scalpels would become impeded in the ex-model's body. Just a sly slip and she would be maimed for life and Callie couldn't see anything wrong with that.

"Chances are she works in a department that you have nothing to do with. Like Derm or something," Mark responds as he tries to find a silver lining to this surprising development.

"Damn," Callie exclaims with a slight pout as she starts to breathe a little easier because Mark is talking sense. "I hope she's in Derm as they have a really nice raspberry cordial."

"Or she may not be surgical," Mark adds as a pager interrupts their conversation. Glancing down at her hip, Callie sees that she is being paged to the ER.

"Ok, here are your instructions. Since you are the biggest gossip in the hospital, find out where she works. I don't care how. Just find out. But maybe keep your pants on as you just declared your undying love for Little Grey."

"Roger that," Mark replies with earns him a confused look from Callie. "I'm slipping into spy mode," Mark explains as if it's the most obvious thing in the world.

"Ok…just don't do anything stupid. And then come and tell me. Also, keep me away from LVAD wires and baked goods; I don't want to become any more like Stevens. Tackle me if you have to," Callie says with a small grin. "I had better go and answer this page," Callie adds as she jogs off in the direction of the ER.

"I'll make you proud Torres! Sloan over and out," Mark yells as he glances around for his first target.

Jogging in the direction of the ER, Callie's mind is in turmoil at the appearance of the fiancée. Callie has been in this exact situation before when her husband's affair would stare her in the face every day. What a way to make Callie feel inferior in every sense of the word. It had taken Callie months to find a level of acceptance that she had married for all the wrong reasons and that it just wasn't meant to be. But even now, Callie and Izzie kept their distance to avoid the painful memories of love that was taking away in the most brutal manner.

Stepping into one of the trauma rooms, Callie barks at one of the interns "What have we got?" A surgery is just what the doctor ordered to keep Callie's mind occupied and off the debacle her life has become. The sheer pace of movement in the room means that Callie's unsure of who is in charge and as an attending, she takes that role. One intern is setting up an IV line in the child's arm while another stabilises an injured leg.

"Eight year old, male child. Was a backseat passenger in a car in a multi-vehicle crash. Tenderness in abdomen area and fractured right femur are the noticeable traumas on the body," the intern quickly reports. "We've already cleared time for a CAT scan."

"Alright, page Karev and get an OR prepped," Callie says as she glances around the room to find the Peds attending on the case. And it's at that moment that Callie's world tips and time stops as she stares into the depth of those brilliant blues eyes. The fiancée is so not in the Dermatology Department unless a symptom of a broken leg is a skin rash. "Oh shit," Callie mumbles under her breathe as she checks the blonde's hands for sharp implements.

The blonde seems to be reacting no better as Arizona's mouth has dropped open in shock as she comes face to face with the mistress. The last time Arizona had seen this woman she had been desperately trying to find her pants as the horizontal tango with her fiancée had been interrupted. The chance of the mistress working at Seattle Grace is a statistical anomaly and Arizona pinches herself to ensure this isn't a nightmare. To Arizona, it seems as if the gods are playing a cruel joke on her and trying to make her an alcoholic by throwing this in her face. Vowing to show no emotions to this woman, Arizona breaks the staring contest as she prepares the patient for transport with not a single word uttered between the two of them.

"Dr Torres, Dr Torres," an intern yells out as they prepare to move the child and Callie is still staring dumbly at the blonde. Shaking her head to re-focus her mind, Callie pushes the appearance of Arizona to the back of her mind and steps back. There is a child to operate on and Callie can't be focussing on her lamentable private life. The two women successfully move the child without incident as they wait for the CAT scan to appear.

Sitting in the CAT office, the two women sit side by side as the blonde acts indifferent to Callie's presence. Last night, Callie had thought the blonde looked scrappy with her fiery responses to discovering the affair. But today, Arizona seems calm, collected and completely unconcerned that her fiancée's mistress is sitting next to her. Callie had expected a rant laced with insults or a good old fashion beating and instead she got ice, cold silence.

Arizona continues to stares straight ahead as Callie gives discreet side-ways glances in an attempt to get a reading on the blonde's mood. But before the scan appears, they are rudely interrupted by an out of breath Mark Sloan who is acting as if he had run a marathon. With his usual lack of social etiquette, Mark launches into what he has learnt about the fiancée after badgering some nurses. Mark doesn't notice Callie's desperate attempts to get him to shut up with hand gestures and "Shhh" sounds.

"So McHotties's name is Arizona Robbins and she just transferred here from Tacoma General. She's a Peds attending, so she's not in Derm. So just avoid Ped consults and you'll as fine as a mistress hiding inside a wardrobe," Mark rattles off as he finally notices the blonde sitting next to Callie. "Hello Dr Robbins," Mark drawls out as he runs his hand nervously through his hair. "How's life?"

"Just peachy…" Arizona replies as she shoots pointed looks at both surgeons as she wishes the ground would open her up and swallow her whole. Arizona had been congratulating herself on avoiding the situation but then this grey haired surgeon has bought the issue to a head.

"I'm Mark Sloan, Head of Plastics. And you already know Dr Torres, although you may not recognise her with clothes on," Mark says with a trademark grin. Mark can't help himself but bask in the awkwardness that he had created and figures he may as well go all in.

Grinding her teeth together, Callie fights against her natural instinct to kill Mark for his stupidity. "Sloan, you have overstayed your welcome. Go visit Little Grey in the Nursery," Callie snarls out.

"That's the last time I ever do something for you," Mark huffs out as he walks away. "Later Blondie," Mark calls back at Arizona. Before Callie can apologise for her and Mark's behaviour, the scans appear on the screen and both women switch back into surgeon mode. Callie's need to explain her actions will have to wait for a later date.

Transporting the child to the OR and scrubbing in all passes in a blur for Callie as Arizona returns to treating her with indifference. Arizona doesn't acknowledge Callie's existence in the room and simply goes about her business as the ultimate professional. Watching Arizona step into the OR, Callie is left along with her bemusement.

"What is this woman? The ice queen?" Callie mutters to herself as she follows after Arizona as no normal person can act so unconcerned. The two surgeons briefly talk about their patient as they start their own operations on the small body. But once they have started, the OR becomes deathly quiet. For the first time in her attending career, Callie doesn't turn on music in her OR as it just doesn't seem right considering the circumstances.

As the silence stretches in the operating theatre, Callie has the urge to say something, anything to make this less awkward. Arizona is stuck in her presence for the foreseeable future and surely a nurse would intervene in the blonde starting attacking her with a scalpel. "I'm so sorry…" Callie begins to speak as she places the pins to reset the child's leg.

"No, no, you will not hold me hostage and make me listen to your apology. I am removing the spleen of a child. That's why I'm here. That's the only reason. I'm not here so you can feel better," Arizona responds, glaring at the Latina at the other end of the table. The nurses stop moving as they watch the two surgeons talk as they hope for a titbit of gossip.

"But…"

"We operate in silence," Arizona cuts off sternly, leaving no room for argument and Callie concedes defeat. The OR returns to its initial state of silence – which is just the way Arizona wants it. She doesn't want to be reminded of her fiancée's indiscretion even though it is staring at her in the face.

Closing up, Arizona surveys the OR and sees that Callie is also finished and is waiting for her. "Seriously," Arizona mumbles into her mask it seems as if Callie is enjoying making her feel uncomfortable. Arizona expected the Latina to run to the hills but Callie is doing the complete opposite. But there is one thing that Arizona needs to know before she faces Piper tonight. After finding out about the affair, Arizona had no contact with Piper other than a million unanswered calls, unread texts and unheard voicemails clogging up her phone. But tonight had been pencilled in as the showdown and Arizona just needs one answer.

Scrubbing out together, the two women stand side by side as Arizona decides to ask her one question. "Just tell me one thing because you owe me that much," Arizona quietly says as she breaks the deafening silence. "How long?"

Callie frowns at the question as there is no way to lessen the blow that is coming. "Three months or so," Callie responds as Arizona backpedals as if she has been physically hit. Callie holds out her hands to steady the blonde but this causes Arizona to shrink back even further. Arizona takes on the pallor of death as she sinks to scrub room floor, shocked at the length of the deception. Arizona had expected a single incident or a week at most – not months.

Arizona knew that her relationship with Piper was on the rocks and a wedding between the two of them was becoming less and less likely. They had started to live separate lives and neither party seemed to notice or mind. But Arizona still can't believe that she had been so blind. Her fiancée had been screwing another woman for months while Arizona had commuted back and forth to Tacoma General. Arizona had well and truly been played the fool.

Callie feels the need to explain herself as Arizona hides her head in her hands. "I'm so sorry, I didn't know that you existed," Callie explains and immediately realises that this reason is really not going to put the blonde's mind at ease. "It didn't mean anything to me, it was just sex," Callie adds, knowing that the words offer little comfort. Cheating is cheating – whatever way it is worded.

"Please, just leave me alone," the blonde whispers out, still not directing any anger at Callie. Seeing the clearly distressed woman on the floor, the last thing Callie wants to do is leave. But from experience, Callie knows that Arizona will need time to process this new piece of information.

"Do you want me to call someone?" Callie asks, as right at this point in time; Arizona needs a shoulder to cry on. When George cheated, Callie had Mark and Christina to pick her up off the floor.

"No, there's no one," is Arizona's muffled reply as Callie stands awkwardly in the doorway. As sweet as Callie's offer is, it just nails home the reality of the situation that Arizona is all alone in Seattle. Working out at Tacoma, Arizona's free time was spent commuting between the hospital and their apartment. In the eight months she'd been living in Seattle, Arizona had made no friends which hadn't come from an introduction from Piper. And the last thing Arizona wants to do is seek comfort with one of Piper's friends as lawyers always think someone else is to blame. Arizona is all alone in this world with no one to help pick her up off the floor. With one last glance at the forlorn figure on the floor, Callie lets the scrub room door swing shut returning the women to their own personal purgatory.

The rest of the day passes in a blur of Mark badgering her to talk about her feelings and Callie secretly stalking Arizona. Callie felt drawn to the blonde and would do anything to lessen her pain, although the blonde hid it well. The way that Arizona interacted with the kids on the Ped's floor brought a smile to Callie's face. Arizona had a way with children that had left Callie speechless – she played games with them, watched cartoons and alleviated their fears when needed. It is clear to Callie that Arizona is that one in a million person who must have some sort of super magic smile because kids generally made terrible patients.

But finally the day is done and Callie plans on holing herself up in her apartment and pretending that all is good and right in her life. Seeing the elevator doors begin to close in front of her, Callie quickly slips through so she can escape the hospital and all its drama. But the drama is now staring at her with those brilliant blue eyes. Standing awkwardly next to the woman whose life she inadvertently destroyed, Callie wonders if small talk would be appropriate. "So I had an interesting day, how was yours?" Callie asks, playing nervously with her jacket sleeves.

"We don't have to do this, talk about what happened. I don't want to relive the moment and from your expression last night, you don't want to either. It's a big hospital, lots of floors, lots of places to hide. I'm quite happy to pretend that I don't know you and haven't seen you naked," Arizona replies as she keeps her emotions well hidden from the Latina as her side. Since realising that her nightmare has followed her to work, Arizona had been trying to get a reading on Callie's angle.

"You're not hearing me Arizona. I know that everything in your life is kind of insane right now. But I figured even you could use a friend. And I make an awesome friend and even greater drinking partner." At Callie's offer, Arizona remains silent and stares at the elevator doors. "And now you probably think I'm insane…" Callie adds at the lack of response.

Finally the door dings open on Callie's floor and the Latina reluctantly concedes defeat for a second time and heads off. Arizona has made it perfectly clear to Callie that she wants nothing to do with her. Not the Callie blames her as she if after all her fiancée's mistress.

Seeing the Latina leave, Arizona's façade begins to crumble as her emotions begin to overwhelm her again. But before the doors can close and return Arizona to her solitude, an arm is stuck back through the gap as Callie gives it one more roll of the dice.

"I know you said you aren't interested. But here's my phone number if you need anything," Callie says as she quickly scrawls her number on a prescription pad. "So if you need to talk, a shoulder to cry or someone to beat up…I have more perspective on this situation than you might think." Callie says as she offers the piece of paper to the blonde. Seeing the sincerity shining out of Callie's eyes, Arizona takes the offered piece of paper even though she has no intention of using it.

"Thanks," Arizona mumbles out as the doors close for good this time.