AN: This is my first Grey's fic! I'm usually off in the land of CSI:NY but I recently became obsessed with Grey's Anatomy. This story is set mid-season 5. Mark and Lexie are together.

"Another shot of tequila, Joe," Meredith Grey said to the bartender.

"Ah, tequila. Brings back memories," A female voice said as she came to sit next to Meredith. She was tiny like Meredith with long blond hair, blue eyes, and appeared to be in her mid-twenties. She was wearing a sparkly black tank top with a pair of jean shorts.

"Good or bad?" Meredith asked.

"Both," she said smirking.

"Me too. I'm Meredith."

"Kayla."

"So, Kayla what would you like to drink," Joe asked.

"I'm in the mood for some tequila," she replied. Joe gave her a shot and she downed it, barely flinching.

"I see. You're like Meredith. I bet you hold your liquor well," Joe stated.

"I've been told. Besides, I wanna get shitfaced tonight."

"So, is it a drinking night?" Someone from behind the two women asked. They both turned to Derek.

"Derek Shepherd! You are in so much trouble!" Kayla shouted before he could lean in to kiss Meredith. She stood up and gave him a hug, much to Meredith's surprise.

"Why haven't you called?" Kayla asked, hitting him in the chest.

"I've been busy," he said defensively, "I see you've already met Meredith."

"So this is the infamous Meredith Grey," Kayla said looking at Meredith, "The newest member of the Dirty Mistress Club."

Meredith stiffened. Who the hell is this girl? How does she know about me? She wondered.

Seeing Meredith's confused expression, Derek quickly said, "Mer, this is Kayla Sloan."

"Sloan? Derek I'm having some deja vous right now," refering to the time when she first met Addison.

"Don't worry Mer, she's Mark's little sister," Derek said.

"Speaking of the other dirty mistress, where is he?" Kayla asked, looking around.

"He should be coming soon. He got caught up at the hospital."

Derek sat down next to Meredith and the three sat there waiting for Mark in a semi-awkward silence.

Twenty minutes later, Mark walked in and spotted the three.

"Well, if it isn't the man of the hour," Kayla said, rolling her eyes.

"Kayla! How are you doing, sis," Mark asked, giving her a hug.

"Mark, how come you never told me you had a sister?" Meredith asked, "For a second I thought she was your wife."

"Wife? Please. I'm never getting married." Mark scoffed, "I never told you because you never asked."

"Really, Mark? You're never getting married?" Kayla said, "Because I recall when you and Derek were 17, Derek also said he was never going to get married."

"Yeah, well he's Derek. He's whipped."

"I am not!" Derek said, offended.

"Maybe not with Addison, but now you definitely are," Mark said smirking at Meredith.

"Derek, from what I heard from your mom after she visited, you're totally whipped," Kayla said, giggling.

"So, Mark. Have you got any special ladies in your life. Or are you still sleeping with anything that breathes," Kayla asked, "You're lucking I'm not like you after the examples you set for me when I was younger."

"You better not be," Mark said, frowning, "I don't like the thought of guys sleeping with my baby sister."

"Mark, I'm not a baby anymore."

"Believe me, I've noticed," Mark said, smirking.

Kayla gave him a disgusted looked and said, "Perv."

"Hey! I'm allowed to look at you. You're my sister."

"Yeah, I'm pretty sure that's why you're not allowed to look at me," Kayla said, hitting his shoulder, "You never answered my question. Are you seeing anyone?"

"Actually I am."

Derek pulled away from Meredith, who had previously been oblivious to the conversation because he was too busy making out with Meredith. "Mark? You're seeing someone and you didn't tell me?"

Mark hesitated. Derek would kill him if he figured out he was with Lexie. "Yeah, we've been dating for a few months, but we're going slow."

"A few months? Kayla said, falsely surprised, "Aww. My little man whore has grown up," she teased, pinching his cheeks.

"What about you Kayla? Do I need to kick anyone's ass?" Mark asked.

"No, and even if there was I wouldn't tell you."

"Why not?"

"You just explained why. Besides you're kind of a jerk to people I date," Kayla said glaring at her brother and hitting him again.

"Ow! Kayla! Why do you have to be such a bitch!" Mark said rubbing his shoulder.

"Because you're an ass," she replied, hitting him again for good measure.

"Touche," He said holding his hands up in mock surrender.

"So when do I get to meet the girlfriend?"

Yeah Mark. When do we get to meet the girlfriend?" Derek asked, "Who would want to go out with you for a few months anyway?"

"Maybe he used his McSteamy moves on her," Meredith said, taking another shot. She had lost count of how many she had but had enough to be drunk.

"McSteamy?"Kayla asked, raising her eyebrows at Mark.

"Meredith and her other friends gave us McNicknames when they were interns. They are residents now. Derek was the first to get one. He's McDreamy. I'm McSteamy."

"Right."

"Addison was McWife, Finn was McVet, We've also called Derek McBastard and McAss," Meredith said, taking yet another shot of tequila.

"Who's Finn?" Kayla asked, "And Derek, what did you do to make the interns call you ass and bastard?"

"It's a long story. A really long one. Finn was a vet I dated at the same time as Derek," Meredith answered, her voice slurring.

"Wow. So let me see if I can figure out this story from what I've heard. You and Derek dated and then he dumped you for Addison. The he divorced Addison and you dated him and Finn? They you two broke up yet again, and Mark told me he dated the plant, Rose. And now you two are back together." Kayla said.

"Maybe it isn't that long of a story," Meredith said. Her eyes started to droop and she leaned against Derek.

"So that's the story. Who are the other residents?I need to know this stuff." Kayla said.

"Wait. Why do you need to know this stuff?" Mark asked confused.

"Did you really think I came all the way to Seattle to see your ugly face?" Kayla teased, " I got a job here. I start tomorrow."

"What? Why didn't you tell me?"

"I just did. Besides, I wanted it to be a surprise. So, surprise!" She said giving him jazz hands.

"So you're actually coming to work at Seattle Grace. You're not just shitting with me?" Mark asked surprised.

"Yes, I am working at Seattle Grace. And when have I ever shitted with you?"

"Well, I can think of a few times," Mark said, glaring at her.

"So can I," Derek said, "Remember when she told you she slept with Todd Hudson. When you went to beat him up, he ended up being on the wrestling team and he beat you up."

"I remember," Mark said glaring at her, "I can't believe you lied about sleeping with him."

"I was only getting back at you for the time you put that tarantula in my backpack!"

"I did that because you told half of the school I had syphilis!"

"I did not! I told that girl you liked, Jody Harrison. It's not my fault she told her friends, who told half of the school. And that was because you-" Kayla started before she was cut off by Derek.

"You know we could continue, but it would take all night to see who was really to blame."

"True," They both said, laughing.

"So you're staying in Seattle," Mark said smiling.

"Yes! Are you in shock or something?"

"No, I'm just happy that we are reuniting the three musketeers. Together we can fight against Grey, Yang, Evil Spawn, Dr. Model, and Bambi!"

"Come again?" Kayla asked, confused.

"The Fab Five."

"That doesn't help me, Mark," Kayla said getting frustrated.

"Meredith and her other intern friends. Or I guess they're interns now," Mark said sighing because it took so long for Kayla to figure it out.

"See? That wasn't too hard?" Kayla teased.

"Shut up."

"Well, I hate to break up this big love fest but I have to go," Kayla said sighing. It was already 2 in the morning and she had to be at work early.

"Yeah, I have to get Mer home," Derek said, trying to pry the shot glass from Meredith hand, "She'll be pissed in the morning if I let her get any drunker."

"You are totally not whipped," Kayla said sarcastically as they left.

"Mark are you leaving?" Kayla asked him after Meredith and Derek left.

"I'm just going to stay a little longer," Mark replied.

"Bye Mark," Kayla said, kissing his cheek, before putting her jacket on.

"Oh, and Kayla,"

"It was nice seeing you. I'm glad you're staying," Mark said without turning around.

"Me too, Mark," Kayla said smiling, before she walked out the door.

AN: I was planning on having this as a one shot but I kinda want to continue. Unfortunately, I've been busy lately, so for now, this is a one shot. I'll try to continue this if I have time.