A/N: This story is set towards the end of the seventh season in Grey's Anatomy and the fourth season of Private Practice. It's going to be a multi-chapter story (not sure how many chapters yet) and each chapter will be named after a popular first dance wedding song to go along with the story's wedding theme. I hope you like the first chapter, and please review – I love hearing what you think! :)

With or Without You

Chapter 1: Amazed

"Hey, Archer; this is a surprise," Addison said, as she let her brother into her beach house. "What are you doing here?"

"Addison," Archer grinned, hugging his sister tightly, "it's so good to see you."

"Yeah, it's good to see you too but, seriously, Archer, what are you doing here? And what do you want?"

"How do you know I want something?" Archer asked defensively. "Can't I just be visiting my favorite sister?"

Addison raised her eyebrow skeptically. "What do you want, Archer?"

"Have you noticed anything different about me?" Archer asked, ignoring Addison's question.

Addison gave her brother the once over: his hair looked practically the same as it had the last time she had seen him, he still dressed impeccably, and he still had the same slim but muscular build. Nothing seemed different. "Have you lost weight?" she asked, fumbling to think of something.

"Actually, I've gained three pounds," Archer said dryly, "but thanks for bringing that up."

"Oh, um, sorry, I guess," Addison apologized with a shrug.

"Don't be," Archer grinned. "I'm happy…that's the difference, Addie. I'm really, truly, undeniably happy. And you'd put on a little weight too if you had a fiancé that bakes as well as mine does."

"A what?" Addison asked is surprise. "You have a what?" she asked again, putting her hand against the wall in an attempt to stabilize herself. Archer couldn't have a fiancé.

" I'm engaged, Addie! I'm engaged!" Archer declared gleefully.

"Oh, wow, um, congratulations, Archer. That's…that's wonderful," Addison stammered, still fighting the dizziness that had come over her ever since Archer had first dropped the word 'fiancé.'

"Thanks," Archer beamed. Then looking at his sister, he asked, "You okay, Addie? You look a little pale."

"Um, maybe we could sit down," Addison suggested. "It's just a lot to digest, that's all." That was the understatement of the year; digesting the fact that Archer was engaged, and happy about it, was like digesting cardboard. Her brother belonged to an exclusive tier of man whores, reserved only for the biggest and most shameless man whores. She was pretty sure that he and Mark Sloan were the only two members. And, lately, Mark had been turning over a new leaf.

"Good idea; let's sit down," Archer said, cutting into Addison's thoughts. "This way we can hash out the details of the wedding."

"The wedding?" Addison choked out, as she sat down on the couch. This was all too real.

"Addison, I know it's been a while since you did the whole marriage thing, but you know as well as anyone that an engagement culminates in a wedding. So, yes, I want to discuss wedding details with you."

"Wh-why?" Addison asked.

"Because you're my best man," Archer answered, as if it were obvious.

"I'm your what?" Addison asked breathlessly, pinching herself on the arm. This had to be some kind of awful dream.

"My best man," Archer repeated slowly.

"You know, Archer, that's traditionally a guy's job," Addison retorted. "Just in case the whole 'man' part of 'best man' didn't give that away."

"Nobody cares about that crap anymore," Archer said flippantly. "Besides, the maid of honor is a man, so it's actually pretty perfect. And it's not like I have any close guy friends anyway. Men don't really like it when you sleep with their wives or girlfriends."

"I could have told you that," Addison said dryly. "Oh, and in case we're keeping score, women don't like it when you sleep with their husbands or ex-husbands or whatever."

"So I take it you're still pretending to be in love with Sam?" Archer asked smugly.

"Shut up, Archer."

"Come on, Addie, don't be coy with me. What's the deal with you two?"

"Sam and I aren't together anymore," Addison informed her brother.

"Oh thank goodness!" Archer exclaimed. "I feel like there should be a choir somewhere over our shoulders singing a couple choruses of 'Hallelujah,' don't you?"

"Not really," Addison answered flatly.

"Addison, this is a good thing. Trust me. I know it might hurt now, but you and Sam did not work. I mean, even Beethoven could have seen that."

"Beethoven was deaf, not blind, Archer," Addison said dryly.

"Whatever," Archer said dismissively. Look, I like Sam. A lot. But come on, Addie, admit it, you were in a weird place when you dated him. I mean, I don't think I ever saw you so unhappy."

"Geez, Archer, don't hold back," Addison retorted. "And I'm not hurting," she added angrily.

"Well, that's the spirit," Archer said encouragingly.

Addison glared at her brother, "Look, Sam and I wanted different things and, you're right, I wasn't happy, and neither was he. So we broke up. It was very adult."

"So you guys are on good terms?" Archer asked.

"We're okay," Addison answered cautiously.

"Good, because I want to ask him to be one of my groomsmen; you're okay with that, right?"

"It's your wedding, Archer," Addison told her brother, still trying to wrap her head around how weird that sentence felt coming out of her mouth.

"Good," Archer smiled. "So, my groomsmen are gonna be Sam, Mark, and Derek."

"Oh my God; I slept with all of your groomsmen," Addison groaned, massaging her temples with her hands.

"Here, have a muffin," Archer offered, pulling a bag of muffins out of his travel bag. "They're really good, and they'll make you feel better."

"Thanks," Addison said, accepting the baked good from her brother.

"Good, right?" Archer grinned, as Addison took a bite.

"Yeah," Addison agreed. "Hey, Archer, where did you buy these muffins? I feel like I've had them before."

"Oh, my fiancé baked them. She's a fantastic baker, and muffins are her specialty. Funny story, Addie, you actually-"

"I still can't believe I've slept with all of your groomsmen," Addison interrupted. "How awkward is that?"

"Don't worry about it, Addie," Archer reassured her. "Iz and I both faced and overcame what should have been fatal diseases or conditions, so we don't care if our wedding is the picture of appropriateness. There's more to life than that."

Addison nodded. When did Archer become such a grownup? Maybe this Iz woman was good for him.

"So, it doesn't matter if you slept with all of the groomsmen," Archer continued. "Izzie's ex-husband is her best man. That's a lot more awkward and inappropriate, don't you think?"

Addison swallowed hard as the pieces of the puzzle began to fall into place – Izzie...the muffins…the surviving what should have been a fatal disease…the ex-husband…Izzie. It couldn't be the same Izzie from Seattle Grace. Fate or bad luck or maybe a bit of both had convinced Addison time and time again that the phrase, 'it's a small world,' was more than just a cliché; but maybe, just maybe this one time she could catch a break. There had to be more than one person named Izzie who baked incredible muffins, had survived a fatal disease, and had gotten a divorce. There just had to be.

"Uh, tell me, Archer," Addison began hesitantly, "what's Izzie's last name?"

"Oh that's the great part," Archer grinned, as Addison tried to calm her nerves by putting another piece of muffin into her mouth, "you already know my fiancé. You worked with her in Seattle. I'm engaged to Izzie Stevens!"

"So, wait," Addison clarified through a mouthful of muffin, "if you're engaged to Izzie Stevens, that means her maid of honor is-" but before she could get the name out, she began choking on her muffin.

Archer, who was too wrapped up in his own excitement to notice his sister's predicament, clapped his hands together gleefully, "That means the maid of honor is Alex Karev!" he declared. "You know, he's actually a pretty good guy, Addie, and I like him a lot…considering he's my fiancé's ex-husband and all. Izzie told me that you worked pretty closely with him back when you were in Seattle," Archer went on, as Addison continued to choke. "Oh, shit, Addie!" Archer exclaimed, finally turning his attention to his sister. "Don't worry, I'm CPR certified," he reassured her, as he hit her forcefully on the back.

"Seriously, Archer," Addison complained, once she had stopped choking. "Were you trying to sever my spine? What kind of CPR was that? Aren't you supposed to be a doctor?"

"Are you still choking?" Archer asked his sister smugly.

"No," Addison admitted, rolling her eyes.

"Yeah, I noticed that too. So I believe the appropriate response should be, 'Thank you, Archer.'"

"Thank you, Archer," Addison muttered.

"See, that wasn't so hard, was it?" Archer teased. "Anyway, I should have been prepared for this."

"Prepared for what?" Addison asked in confusion.

"I should have seen this coming," Archer explained. "When Izzie and I told Alex that you were my best man, he spit his beer out all over me. I think it was accidental, but I am marrying his ex-wife, so it's hard to be completely sure. Anyway, beer in the eye hurts."

"I'll keep that in mind," Addison said dryly. "So Alex, I mean, Karev…Karev is on board with this?"

"I mean, he's not thrilled," Archer confessed. "But can you really blame him? He and Izzie didn't exactly end on the best of terms. But he came around, and that's all that matters. And I think it's okay if you call him Alex," Archer said. "After all, you two are the best man and maid of honor; you're gonna get to know each other pretty well."

"Right," Addison sighed, running her hand through her hair.

"And, hey, look at it this way," Archer continued, "at least there's one man in the wedding party that you didn't sleep with."

Addison glared at her brother.

"Oh," he said in surprise. "So you slept with Alex too? Uh, good for you, I guess."

"Shut up, Archer,"

"Hey, look at it this way, I'm in the wedding party, and you didn't sleep with me so, there you go, there is one guy in the wedding party that you didn't sleep with. Kudos, Addie!"

"I'm serious, Archer. Just because you're engaged now doesn't mean you can act all entitled."

"Can you blame me?" Archer asked with a laugh. "My best man slept with my fiancé's maid of honor. Isn't that rich?"

"It was a one time thing right before I moved to LA," Addison explained. "Nothing came of it…and I think us sleeping together is one of the few secrets that hasn't gotten out at Seattle Grace, so I'd appreciate it if you didn't say anything to anyone."

"Okay," Archer agreed. Then with a smirk he added, "Only you would find a way to sleep with both sides of the wedding party. Only you."

"Shut up. You can't talk," Addison retorted.

"I'm not saying anything. I actually find it endearing. So, anyway, Alex and Izzie are at our hotel dropping off our things and getting ready for tonight. I figured we could all come over to your place for a little bride, groom, best man, maid of honor thing."

"Wait, tonight?" Addison asked in surprise.

"Yes," Archer nodded. "Does seven work for you? I already found a place where we can get appetizers and dinner from, so you don't have to worry about cooking."

"How considerate of you," Addison said sarcastically.

"I thought so," Archer grinned. "So, I'll see you at seven," Archer said making his way towards the door. "And thank you so much, Addie, for agreeing to host dinner at your place. You're already proving to be a great best man."

"I didn't really have a choice in the matter," Addison mumbled angrily.

"Great, I'm looking forward to tonight too," Archer said, completely ignoring her. "See you in a couple of hours, Addie!"