A/N: Okay, I recently saw a prompt and this story just popped into my head. This is obviously an AU and you can find all necessary background information in the story itself. I hope you'll enjoy this story and I'd love to know your opinions. Feel free to leave a review :)

Disclaimer: I don't own any of the Grey's Anatomy characters.

Not a Double Date

"Please, Lexie! Please, please, please!"

"Mer, come on. Do I have to?" I asked looking miserably at my older sister. No, I was not on board with her plans at all.

"Well, you do not have to," she relented and looked at me with puppy-dog eyes. "But I would very much appreciate it."

"Mer, quit the guilt trip. It's not gonna work this time. What would I even be doing there?"

"You would be having dinner at your favorite Italian restaurant with your favorite sister and two very handsome young men," she tried to tempt me. "That doesn't sound too bad now, does it."

"First of all, don't let Molly and Maggie hear that. And while I do love you very much, please don't make me do this." Yes, I was begging by now. "Second of all, how would you even know that there will be two handsome young men? I thought you'd only met one of them before."

"Well, technically … I did," she admitted. "But since Derek is very very handsome, I figured that his friend should be at least handsome. Besides, don't you always say looks aren't everything."

"Exactly! Thank you, Mer. That would be my next point. You don't even know this Derek-guy's friend. He could be a womanizing creep, who is only interested in getting into my pants, for all we know."

"Lex, calm down. I'm not trying to set you up with him," she tried to reassure me. "We don't even have to call it a double date, if you don't want to. We can just call it … um … four people going to dinner to get to know each other better; and of those four people only two have any kind of romantic interest in each other."

I sighed and paced through the kitchen of the apartment we shared together since I started college. Having known my half-sister my entire life, I was now certain of one thing: if she was so desperate to get me to come with her, she must really like this Derek-guy. And that's how I knew that I'd almost lost the fight: I was and always had been a pushover and a sucker for romance. Seemed like I'd be going to this dinner. "Just four people having dinner together. No obligations and afterwards we can go our separate ways?"

"Yes!" Meredith's eyes lit up happily. "You just have to be there, smile, make polite conversation and eat your delicious Italian food. For which I will pay of course."

"Mer, you've got it bad … really bad, haven't you?" I laughed.

"You'll understand once you meet Derek," she said dreamily. "And he assured me that his friend is a decent guy. We'll just call it meeting each other's families."

"Ha, you don't honestly think that this will keep poor McDreamy from meeting mom, dad, Ellis and Richard, do you?" I grinned.

(Okay, just for explanatory purposes: many many moons ago Ellis and Thatcher Grey were married and had a baby girl, Meredith Grey; they both fell in love with other people and separated amicably; Ellis married Richard Webber and they had a daughter, Margaret Webber; Thatcher married Susan and they had two little girls, Molly and me. Because Ellis and Richard were surgeons and therefore had very busy schedules, Meredith was raised by Susan and Thatcher along with Molly and me. In return, all three of us would spend a lot of vacations with Ellis, Richard and their daughter Maggie. In conclusion, we were one unconventional, big, happy patchwork family and none of us would have it any other ways. However, any prospective suitor would have to go through the hardship of meeting not only one, but two sets of parents. Anyways, back to the story.)

"McDreamy? Seriously?" I just smirked at her and she sighed. "Well, it does kind of fit him." Now it was her pacing through the room. "God, who am I … this isn't me. I don't go crazy about a guy I literally just met."

"Relax, Mer. It had to happen sometime." I winked at my sister. "One of these days you'll turn out to be a hopeless romantic just like me."

"Yeah, Lex. I wouldn't count on that happening." Mer laughed and put an arm around my shoulders. "Anyway, does this mean you'll come?"

"Yeah, yeah, can't let my favorite sister down now, can I?" I relented.

Meredith squealed – I almost didn't trust my ears – and threw both arms around my neck. "Thank you so much, Lex. You will not regret it, I promise. We'll have a great evening. Oh, I've got to call Derek and tell him I finally wore you down. And then I'll need your help to pick out an outfit."

Just for the record, I – the girly one out of the two of us – was dressed and ready to go in under an hour. I wore a simple dark red dress with sleeves that stopped at my elbows. I wore my long brown hair loose and in soft curls and applied my make-up very subtly – just a bit of lip-gloss and mascara. While I was putting on my black pumps, I heard Meredith scream from her room.

"I officially have nothing to wear." Sighing and rolling my eyes I stood up and went into my sister's room. "And God look at you. You look gorgeous. Derek will take one look at you and forget all about me." One thing you have to know about my big sister is that behind her confident and collected outward appearance, she hid a huge amount of insecurities and self-doubt. Ellis Grey has always had very high expectations for her eldest daughter and Meredith often felt like she couldn't live up to them. Mostly growing up with my parents protected her a lot from Ellis' criticism, but not completely.

"Mer, pull yourself together. You have a closet full of beautiful clothes to wear, all of which you will look amazing in." I said while going through her closet looking for one particular dress. "Derek will take one look at you and not even realize that you little sister is in the same room. He will probably even forget his own friend is there. And if it would make you feel better, I can go take off the little make-up I put on, change into some leggings and an over-size sweater and pull my hair into a ponytail. Would that help?" I joked.

"You know I didn't mean it like that," Mer said not quite meeting my eyes. "You'd actually do that?"

"Are you kidding? I would love to go out in my comfy clothes, just say the word." I winked while handing her the dress I had been looking for. It was a very dark emerald green with a sash around the waist. Basically, it was rather simple just like my dress, but it still looked a little more elegant. "Now, go put on that beautiful dress and do your make-up. I'll be waiting in the living room."

"Thanks, Lex." Meredith called after me while I was walking out of her room.

"No problem, sis."

Without any further discussions or complications, we arrived at the restaurant right on time. I let Meredith go in first; after all, she knew whom we were looking for. The waiter led us to table that was already occupied by two men. Admittedly two very very handsome men; Meredith had not exaggerated. I looked at my sister and could see a big smile spreading across her face at the sight of the men – though it was probably directed mostly at one of the two. Seeing us, they stood up and one of them – the one with perfect brown hair and blue eyes – approached us.

"Meredith, it's great to see you again." He greeted my sister with a hug and a sweet kiss on the cheek.

"Hello Derek, it's nice to see you too." Meredith said and the gestured to me. "I'd like you to meet my little sister, Lexie. Lexie, this is Derek."

I started to hold out my hand to him, but instead he enveloped me in a hug as well. I must have looked a bit shocked because I could hear my sister and Derek's friend chuckling and Derek looked at me sheepishly. "Sorry, I come from a family of huggers."

"No problem at all," I laughed and patted his arm. "You just took me by surprise."

"Well, it's really nice to meet you, Lexie." Derek said with a charming smile and I can't help but think that the nickname fits him perfectly. "And I would like the two of you to meet my best friend and honorary brother, Mark Sloan."

Mark was a bit taller than Derek with blond hair and blue eyes. He approached us with an equally charming smile. "It's nice to meet both of you. And while I am an honorary member of the Shepherd family, they have not yet converted me into their hugger-ways." He held his hand out to Meredith first and she shook it.

"I'm not much of a hugger either, so that's perfectly fine with me. It's nice to meet you," she said.

"Likewise. I've already heard a lot about you, Meredith, so the pleasure is all mine." Mark grinned and turned to me. We shook hands and I could have sworn that he held on to my hand a little longer than necessary. "It's very nice to meet you too, Lexie." I smiled and with that all formal introductions were made, and we took our seats.

Now, even though I was completely against going to this dinner, even I had to admit that it wasn't half bad. Meredith and Derek actually made a really cute couple and kept the conversation going without having to try too hard. Mark seemed like funny guy and his relationship with Derek was hilarious. The stories they told about their childhood and the mischief they had committed had Meredith and me laughing like crazy. Even though they were not biologically related, they seemed as close as two brothers could possibly be. When our drinks arrived Meredith and Derek started a rather private conversation, so Mark turned to me.

"So, Lexie." he started. "What do you do?"

"I'm a med student," I explain. "I want to be a surgeon, like Meredith. She's a surgical intern at Seattle Grace Hospital."

"No way, I just transferred to Seattle Grace Hospital. Derek works there too, you know. Maybe you'll join us once you finished med school." We smiled at each other and talked for a while about my studies and his work at the hospital. I guess we could have talked on for hours, but were interrupted by the waitress, Stella, wanting to take our orders.

"So, I hope you are having fun on your double date." She grinned at us. "Are you ready to order?"

"Oh, it's not a double date. We're just third and fourth wheeling," I interrupted her gesturing to Mark and me. Stella looked embarrassed, but relaxed when the four of us started chuckling. We placed our orders and she quickly left our table.

"Wow, Lex. Way to let a guy down easy," Mark feigned a hurt expression. "You just broke my heart."

Derek burst out laughing. "Well man, serves you right for a change." And with that Derek started telling stories about Mark womanizing ways throughout college. Mark repeatedly swore that that part of his life was in the past now and meanwhile kept looking at me from the corner of his eyes. I didn't really know what to make of it. After all, the two of us weren't on a date, so it should be none of my business. But if that was the case, why did I keep stealing glances at him, too?

Soon after, Stella brought our food and the conversation dimmed down while we were eating. The rest of the dinner was rather uneventful but nice, nonetheless. Maybe Meredith was right. Coming with her to have dinner with Derek and Mark wasn't such a bad idea after all. God, I hated it when my sister was right. I was almost sad to see this night end when we paid for our dinner. While we were standing up, Meredith gave me a quick hug and whispered "Thanks" in my ear. "You're welcome" I mouthed back and gave her a reassuring smile that she reciprocated.

We said our goodbyes in front of the restaurant. Mark and I stayed back a little to give Meredith and Derek some privacy. "So …" Mark said.

"Yeah," I started. "I had a really nice time tonight. Who would have thought?"

Mark chuckled. "Me too. I have to admit, Derek had to persuade me to come but I'm glad he did. I'm really glad I got to meet you."

"Me too." I smiled up at him.

"You know," he started. "I think we should do this again sometime."

"Going on a non-double-date?" I asked.

"Sure," he hesitated. "Or maybe … a real double date. Or just a normal date. You know, just the two of us." He gave me a shy smile and I couldn't help but reciprocate. Who would've thought that a former womanizer could be so cute while trying to ask out a girl?

"I'd like that." I got a piece of paper and a pen out of my pocket and wrote down my number. He watched me curiously and then took my number with a smile.

"I look forward to seeing you again," he said and bent down to kiss my cheek. I could feel myself blush.

"Me too." Before I knew what I was doing, I had pulled his head down and kissed him. He hesitated for merely a second before kissing me back. After we pulled apart, I looked at him sheepishly. "Sorry, I'm not usually so forward. I don't know what came over me."

He was quite for a moment. "Whatever possessed you to do that should possess you more often." And with that he kissed me once more firmly on he lips. We just stared at each other until we heard someone clearing their throat.

"You guys finished?" Derek asked with a knowing smirk and Meredith couldn't quite conceal her giggling.

"Nope, we're just getting started." Mark replied. We said the rest of our goodbyes and then went our separate ways.

Meredith and I were walking towards our car in a happy and comfortable silence. That is, until Meredith decided to open her mouth.

"So Lex, anything you'd like to tell me." She grinned at me. I knew she would pry everything out of me once we got home, but not just yet.

"Oh, shut up, Mer." And with that we both burst out laughing.