A/N: I originally wrote this one-shot for my story, Missing Moments – a series of unrelated Jaddison one-shots; because I thought that Addison not going to Seattle after Mark's death was a missing moment if ever there was one. Initially, my plan was to make this a Jaddison story, but as I wrote it, it ended up feeling more like an Addek fic (although there are some pretty heavy Jaddison undertones). I hope you like this story, and thank you so much for reading!

Choke on the Regrets

And you can't see when all your dreams are coming true.
Oh yeah, it's easy to forget.
Yeah, and you choke on the regrets.
Yeah, who the hell did I think I was?
-Goo Goo Dolls

I'm gonna show you something, and when I do, you do not get to laugh, and you do not get to gloat.
-Grey's Anatomy

Derek wasn't surprised when Addison came to Seattle for Mark's funeral. Addison and Mark were close; it would have been awkward if she hadn't come. And Derek wasn't surprised that Addison had brought Amelia with her. Mark had been like a brother to Amelia; it would have been wrong for Amelia not to be there. But Derek was surprised when he saw that Addison had brought along her boyfriend, Jake Reilly. It's not like he was jealous of Jake – after all, he had Meredith. He was just surprised that Addison had brought him along.

Derek tried to keep his eyes from wandering over to where Addison, Amelia, and Jake were sitting during Mark's funeral – but it wasn't easy. Jake was holding Addison's hand, a gesture that both gave her space to grieve and provided comfort. The perfect gesture given the situation. Derek looked over at his own wife, sitting next to him. Sure, they were a stable couple, but Meredith hadn't exactly been attentive to his grief lately. He understood that this wasn't her thing, and he knew that she was dealing with Cristina drama…but still, he couldn't help being a little envious of what Addison and Jake had.

And halfway through the eulogy, Derek remembered why the name Jake Reilly sounded so familiar. Addison had mentioned his name during a guilt-driven late-night phone call that she had made to him, several months earlier. He could tell by the sound of her voice that she had probably drank a little too much red wine (probably the Chilean cabernet that he knew she liked); but he didn't press the issue. He just listened intently as she told him that since he had saved her brother, it was only fair for her to tell him about what was going on with his sister –even though Amelia had made her promise not to say anything to him or anyone else in the family. But she claimed that, over the years, they had already kept enough from each other, and it had gotten them nowhere; so she called to tell him that Amelia was pregnant with a brainless baby, and there was nothing that anyone could do about it. She told him that Amelia had shut her out completely, but that he shouldn't worry because Amelia had sought comfort in the clinic's fertility specialist, Jake Reilly – and Jake was a great guy.

He stole a glance at Jake and Addison. Jake Reilly. He had been there for Amelia, and now he was there for Addison. But Derek wasn't jealous. Amelia was his sister, and Addison was his ex-wife; and both deserved attentiveness. Hell, he deserved it too (not that he was getting it).

And towards the end of Mark's eulogy, Derek couldn't help remembering a conversation that he had had with Mark, several years ago.

"Would you wipe that smug smile off your face already?" Mark asked in disgust.

"What are you talking about?" Derek asked innocently.

"You know exactly what I'm talking about," Mark retorted. "The entire hospital knows that your divorce went through this morning…but you can drop the bright and shiny act."

"But I am bright and shiny," Derek insisted smugly.

"Yeah, we'll see how long that lasts," Mark muttered.

"What are you talking about?" Derek asked.

Mark shot Derek a pointed look. "You're gonna realize that you made a horrible mistake divorcing Addison…not fighting for Addison. You're gonna realize that whatever type of relationship you think you have with Meredith doesn't even scratch the surface of the relationship that you and Addison had. You're gonna realize that you miss being in an adult relationship."

"Mark."

"And you might not realize it today. And you might not realize it tomorrow. And you might not even realize it in a year. But, trust me, Derek, you'll realize it. And by the time you do, it'll be too late because Addison will have moved on. And you'll be jealous because when she moves on, it won't be to some intern she met at a bar. It'll be the real deal. And you'll be jealous."

"She cheated on me with you," Derek shot back. "Do you honestly think I'll be jealous if she moves on to you or someone like you?"

"You already proved that you were," Mark pointed out smugly.

"What are you talking about?" Derek asked in confusion.

"When I first came to Seattle, you punched me in the face. You're clearly not okay with the idea of me and Addison."

"That was about Meredith," Derek disagreed. "That was about you talking to Meredith. You said so yourself."

"Hey, Derek?"

"Yeah?"

"People lie. You and I both know that you punching me had nothing to do with Meredith. But people lie. You're lying to yourself right now if you think you're not going to be jealous when Addison moves on. That it's not going to make you realize how much you took her for granted. That it's not going to make you wish that you were with her, and not with Meredith, or whatever Anti-Addison you're with at the time."

"That won't happen," Derek insisted.

"Trust me, it will. And when it does, I'm going to laugh, and I'm going to gloat, because even though Addison should be the one laughing and gloating, she's too classy to do that, so I'll do it for her."

"We'll see," Derek muttered.

"Yeah," Mark shot back. "We certainly will."

"Hey, Derek," Addison said, ripping her ex-husband from his thoughts.

Derek looked up and saw Addison and Jake standing in front of him. His eyes immediately darted to their hands – which were still intertwined – before he met Addison's eyes.

"A bunch of us were going to go to Joe's to grab a few drinks," Addison began. "We thought that Mark would've liked that. Do you want to come with us?"

"Yeah," Derek nodded. "Yeah, that sounds…good. It's exactly what Mark would have wanted." He turned to his wife. "Meredith?"

"You go," Meredith told her husband. "I, uh…Cristina and stuff."

"Right," Derek nodded sadly. His wife's response didn't really surprise him; but it still hurt.

So he shared a cab to Joe's with Addison, Amelia, and Jake. He sat in the front seat. The three of them sat in the back. And he couldn't help thinking about how if things had gone differently, he'd be the one sitting in the back next to Addison and Amelia – not sitting in the front seat, alone, looking through the rearview mirror at the life that could have been his.

And as he drank with Addison, Jake, Amelia, Callie, Arizona, and Bailey, he only became more bitter. Sure, he smiled good-naturedly when Jake took out his phone and showed everyone pictures of Addison's undeniably adorable son, Henry. And he laughed when Addison, Callie, and Bailey shared their funniest Mark memories. But, inside, he was bitter. He couldn't help noticing the way that Addison looked at Jake, or the way that his hand would lovingly brush against her hand, or how his arm would wrap reassuringly around her waist. But most of all, he couldn't help noticing the spark between them – the spark that had admittedly burned out in his own relationship. Sure, he loved Meredith…but not the way that Addison and Jake loved each other. Not the way he loved Addison.

And just when he thought it couldn't get any worse, it did.

"Hey, can I buy the next round of drinks?" Jake asked, ripping Derek from his thoughts.

Addison looked at her boyfriend, and gave him a loving smile. "That would be great. Thank you, Honey."

Honey. It fell from her lips so effortless…so naturally. Honey. She used to call him that…until he told her not to.

"Wait, did you just call me honey? Don't call me honey."

And as he watched Addison and Jake exchange a smile, Derek would have given anything to be called honey again – to be the one that she called honey.

"I, uh, I have to go," Derek muttered, standing up quickly.

"But, Derek…" Addison trailed off in confusion.

"I, uh, I have to go check on a patient," he lied. "I'll be right back."

He didn't wait for a response – just made his way out of the bar as quickly as he could. He crossed the street, walked into the hospital, and made a beeline for his office, closing and locking the door behind him.

"You were right," he muttered aloud. "Damn it, Mark, you were right."

He ran his hand through his hair in frustration as he thought about Addison and Jake, and their supportive, grown-up relationship. Had he fought harder, that could have been his relationship. That could have been his marriage.

But he hadn't. He had waited too long to figure things out, and just as Mark had predicted, Addison had moved on. Derek sighed heavily as the reality of the whole situation crashed down on him. And he realized that while he didn't know much anymore, there was one thing he knew for certain – wherever Mark was right now, he was laughing and gloating.