A/N: Heeyyy FINALLY THE SECOND CHAPTER. This one I haven't re read, sorry if it's terrible D:

I don't own Grey's Anatomy and such blah blah. :D But please Review, I hope you enjoy. xo MadameSnow 3

Mark was walking through the halls of Seattle Grace, his new scrubs on, with his usual swagger, and enjoying the last few moments he had without seeing Derek who was still in surgery. He needed to clear his head from what happened but he couldn't stop thinking about it at all. He certainly felt relieved so he kind of did him a favour. Maybe that was all it was, a favour. Unless he was cheating Mark out of fooling around with anyone like he said he wouldn't do. Surely that was against the rules. What rules? There weren't even any rules! His head buzzed.

Why would Derek do something like that? In a hospital. Was he just trying to embarrass him? Was he trying to dig something up from the past? He completely humiliated him! What was he up to?

Derek Shepherd walked out of surgery and into the nearest on-call room. He threw himself onto the sofa and put his hands on his face.

"Why did I do that? Why would I do that? What the hell is wrong with me?" He muttered to himself pushing his palms into his eye sockets with slight anger.

"Will I ever be able to get sleep in this room?" Derek heard the familiar high voice ringing through the small room.

"Sorry Dr. Grey. I didn't realise anybody was in here. I'll leave if you want me to." He started to get up.

"No, no. Sit back down, I'm awake now. What is it with you attendings? You and Dr. Sloan barging in here all exhausted but not from sleep..." Meredith coughed.

"Wait... Mark came in here? When? Was... was he... a mess?" Derek asked.

"You know?" She said shocked. "How do you know? Oh my God! You were there when it happened! Explain to me how in the world it happened? Men don't just explode for no good reason. He told me it just happened! In a hospital! What-" she looked at Derek and saw him look at the floor and go a light shade of pink. "Who? You?" Derek sank down lower and flushed even more. "Holy shit! W-wait a second. You're saying that you, Mr Straightest-Guy-In-The-World, did that to him?"

"I'm not saying anything..." he croaked quietly.

"Do you like him?" She asked.

"No! N-no. No... No?"

"Are you trying to convince yourself that you don't?"

"Perhaps," he cleared his throat. "It's... it's weird. I was just teasing him for fun. I didn't realise he was... that – I can't find the right word – desperate?"

"Desperate for what? What did he do?" Meredith exclaimed, confused.

"No, no. Not like that. I'd bet him he couldn't go long without sleeping with anyone without going insane. He just wanted to prove me wrong. He went a month.." he explained softly

"So how did he end up stumbling in here, fully in the middle of what looked like a very powerful orgasm?" Her eyebrows raised.

"Like I said I was teasing him. You know. Like-"

"Boyfriends do?" Meredith interrupted. Derek sighed.

"Hmm... I suppose. Oh my God! Why did I do it?" He put his face in his hands.

"What did you do to him?" She asked carefully.

"You'll judge me horribly." He muttered.

"I won't."

"You will."

"I will not! Now stop being so childish!" She raised her voice.

"Fine! I basically squeezed his junk in a surgery until he came! There." he partly yelled, defeated.

"In a surgery? How did people not notice?"

"Gallery closed, blind spot to the cameras recording the operation, covered by the patient and it only took a few... strokes, which is what I meant by desperate. I mean he doesn't usually come so soon it was- Oh fuck," He sighed realising he'd completely put his foot in it. Meredith just looked at him wide-eyed. "Mark and I have known each other for a long time, Meredith."

"What?" Meredith sat down next to Derek, looking at him intensely "Explain." she demanded.

"Well-" Derek started but was cut off by the door opening. Very typically, it was Mark. Everyone froze. Mark was the first to speak.

"You complete ass!" He threw the scrubs that were in his hand at Derek "I hope you know those are my dirty, stained scrubs and it's your fault! I should kill you! I think I will! You know how much I struggle – and don't say that you don't because we both know that you do." Mark reached for the flower pot on the table but before he could pick it up Meredith interrupted.

"Hey!" she stood up and grabbed Mark's shoulders "Sit down. I already know what happened today but what the hell has been happening before?"

"Nothing has ever happened before why would you even suggest that?" Mark answered a little too quickly.

"Mark... I kind of let something slip." Derek muttered. Mark looked at him wide-eyed.

"We agreed-" Mark started.

"No, he just hinted that it wasn't the first time it had happened." Meredith stuck up for Derek but Mark didn't listen and he continued.

"We agreed the night before you married Addison it was never mentioned again." he said calmly at first but then he raised his voice "Actually, we agreed it would never happen again. So why the fuck did you do this to me today? WE AGREED, DEREK!" Mark put his head in his hands angrily.

"I-I don't even know why I did it. I wasn't thinking-"

"Well obviously! It was your idea in the first place to not do it again. And nowhere in that did it say that if you divorce Addison it would start like nothing had changed!" Mark stood up angrily then Derek did too, pushing Meredith to the side to yell in each others faces.

"I DIDN'T KNOW I WAS GOING TO DIVORCE ADDISON! I thought we were going to die together, still in love. It was you who made sure that we didn't."

"I'm lost." Meredith whispered carefully from the corner.

"Basically me and Derek fucked each other for a very long time but we said we'd never get too attached." Mark gritted through his teeth still looking Derek in the eye.

"Yes. We were just each others 'bit on the side' while we saw other people." Derek replied in the same, tense way.

"Okay. Calm down. Just sit down and explain to me when it started. It might make you feel better." Meredith soothed making them both sit net to each other on the sofa.

"Fine," Derek sighed "It started when we were 15, it was an accident... both of us had girlfriends and well... mine was very possessive..."

[Oooooh Flashback time :D]

Derek was laid on his lawn outside, it was about 11pm and he felt very closed in. Julia, his girlfriend, had been following him and ringing him and the only way he felt better was being outside, he loved the outdoors. He heard rustling so he sat up, searching for the source of the sound. It was coming from his garden fence.

He saw his best friend, Mark Sloan, climbing over. Then, after jumping into his yard, he started swaggering over to him with a bust lip, a huge smirk on his face and he had a rucksack tossed lazily over his shoulder

"Hey Derek," he greeted cheerily. "I got into a fight with that asshole Harry who always stands outside the liquor store. He hit on Jenny. I didn't actually care because she's annoying, but I've always wanted to kick his ass. I think he started crying." He laughed.

"Nice." Derek said distantly.

"What's wrong? Is Julia being a bitch?"

"Yeah... She's obsessed with me. I just need to get away from her." he sighed.

"Oh, well..." Mark reached for his bag and pulled out a bottle of whiskey and a couple of cans of beer "I stole the beer from Harry when he ran away and I stole the whiskey from my dads cabinet. Lets get wasted to forget about our stupid girlfriends." Mark smiled at Derek.

"We have school tomorrow." Derek argued half-heartedly.

"So? I'll stay here for the night. Live a little Derek!" Mark pushed his shoulder playfully.

"Fine." Derek agreed as Mark started walking into his house already.

By 1am Derek and Mark were completely drunk and laughing, talking about Derek's girlfriend. Mark was laughing so much he was crying a little bit.

"Why would anyone date a band geek?" He wheezed hysterically.

"I know! She must have very low standards!" Derek was laughing equally as much.

"Why would anyone screw a band geek?"

"I know!" Derek repeated.

"I'd screw a band geek." Mark said, a little bit calmer.

"Well, if it moves, you can rely on Mark Sloan to fuck it." Derek chuckled.

"Hey, I've only had sex with... 6 or 7 people!" Mark said, shocked.

"You are only 15." Derek stated.

"Well... I haven't screwed you!" Mark said quickly

"Yeah but we all know you'd love to!" Derek joked.

"Mmm." Mark lazily agreed, making Derek worry slightly. Was he serious? He just played it safe and laughed it off. Having sex with Mark... that seemed so weird. They were practically brothers, it would be like incest. But it was also rather exciting to Derek Shepherd's horny teenage mind. Mark was looking at Derek very intensely. It worried him slightly. He saw Mark's face approaching his hesitantly – his heart sped up with excitement – and he could do nothing but stare and let it happen. When suddenly, Mark pulled away and Derek felt disappointment wash over him so overwhelmingly that he grabbed Mark's shoulder's and pulled him towards him forcefully so that their lips crashed into each others. They kissed clumsily for a few seconds before Mark pulled away, confused.

"Wow. What's even going on?" He asked.

"I don't care," Derek panted and reattached their lips, this time Mark moved his mouth along, setting an unsteady rhythm. It felt odd to him at first but then all of a sudden, he felt the same teenage, drunken need that Derek felt. He didn't care that it would be considered wrong or gay, he wanted Derek so badly, it hurt him.

In no time they were panting loudly, in their little bubble, then Mark groaned a little too loudly and then their bubble was popped. Derek stopped kissing him, with reluctance.

"Shut up. My parents are in," Derek demanded. "What are we doing?"

"I'll be quiet." Mark said then he leaned over to Derek pressing his lips softly to his and without even realising, Mark had pushed Derek so that he was on his back, his rough hands running through his glossy brown hair, to his soft, flushed cheeks, to his broadening shoulders, to his warm waist and then they found the hem of his shirt. Mark didn't know why, but he felt an impulse to take off his shirt and feel his bare, hot body against his own. He began to pull the shirt up and Derek, who was fighting lots of groans and moans that were battling to come out of his body, happily obliged. Then, while their kiss was still broken, Derek pulled off Mark's shirt too.

Even though they'd both seen each other naked and shirtless numerous times before, they saw something different this time. They didn't just see their best friend, they saw a good looking, attractive person who they just wanted to grab and do many forbidden things to.

Derek stretched a hand out shyly to touch Mark's more-defined chest and when his hand made contact with his skin, Mark grabbed him and began to kiss him with raw passion. Their bodies were slightly damp and their skin felt flushed and hot and being pressed up against each other was definitely turning them both on.

"Mark, mark!" Derek exclaimed in a hushed way as Mark was moving his kiss to his jaw and neck. Mark took this as a signal to do something more. When Derek felt Mark's hands on his belt, he thought he was going to go crazy with desire. He was getting impatient very quickly and because he'd never had sex with another boy before, he had no idea what to go with all of his built up emotions. He felt like he was going to explode! Mark undid Derek's jeans and while sucking on Derek's neck, he pulled them down his legs painfully slow.

"M-Mark," Derek stammered, Mark stopped kissing him and looked at him "I'm... scared. I don't know what to do." A wave of realisation washed over Mark.

"Me either... I was just doing what felt... right." He admitted slowly. Mark searched Derek's eyes for some kind of signal of what to do next but he just saw confusion. Mark knew what he wanted. He looked at Derek's innocent, flushed face and he just wanted to kiss him and... Then, he grabbed Derek's face and kissed him softly on the lips once. Something in Derek must've clicked because then he sat up and began unbuckling Mark's belt in silence, never speaking or taking his eyes off him. He too slid his jeans off his legs and then he took a mental deep breath and looked down.

He could make out the outline of Mark's hard erection through his boxers and he felt sick with nerves. He wasn't quite sure what to do until he saw Mark's hand grab his own and thrust it into his crotch.

"Please touch me, Derek." Mark whispered. Derek just nodded dumbly and then he realised that he needed to move his hand. Just do what you like he though to himself It's not that difficult. And he began tracing the outline of Mark's cock with one of his fingers, shyly. Then he palmed it with his hand experimentally. After his bravery built up, he wrapped his hand around the clothed length and began moving it slowly up and down. He heard Mark grunt which gave him more confidence and he pulled Mark's boxer's down slightly, exposing his erection. Derek grabbed hold of it and pumped it slowly again.

"Ohh..." Mark whimpered at Derek's touch and then he reached forward and shoved his hand roughly down Derek's boxers and grabbed his dick and squeezed it.

"Shit!" Derek nearly yelled in surprise. He sped up his hand which made Mark do the same. "Oh, ohhh." Derek moaned and panted. How was this even happening to him? The face of his best friend had never been more gorgeous to him and now he was giving him a hand job in his bedroom. Derek could feel himself losing it and because he felt so good, he felt his rhythm slipping and he squeezed Mark several times and then went up and down a few more.

"D-Derek don't. I will cum if you do that." Mark gasped.

"So cum." Derek replied simply.

"How close are you?" Mark ground out through his clenched teeth.

"Very." Derek panted and then he got a shock of pleasure running through him which caused him to squeeze Mark roughly

"Fuck, Derek!" Mark hissed then groaned and tried to be as quiet as he could. Derek felt Mark's cum spill onto his hand and he felt Mark's grip slacken. Mark panted for a few seconds attempting to recover from his orgasm. "You bastard," He said exhausted. Then he lunged forward and, to Derek's shock, wrapped his lips around to tip of Derek's erection.

"OH!" Derek exclaimed loudly. "Mark... s-stop!" He looked down at Mark's head bobbing in between his thighs and he got even more turned on. "Mark I'm going to cum, stop!" Derek whispered urgently. Mark didn't stop. Derek had to reach for a pillow to cover up his mouth so that he didn't wake up his parents because he couldn't help the groans, gasps, moans and hisses that poured from him as he came hard in Mark's mouth. Derek fell back and panted, completely spent. Mark came and laid beside him. The regret hit the both of them like a ton of bricks now that the pleasure had subsided.

"We tell no one." Derek stated.

"No one." Mark agreed.

"Night Mark." Derek got in bed and turned his back to Mark feeling extremely embarrassed and awkward.

[Flashback overrrrrrrrrrrr]

Derek explained to Meredith in full detail and now that he'd finished, Mark was a very pink colour and Meredith's mouth was open in shock.

"Shit." Meredith broke the silence.

"Yup. Unfortunately, it didn't end there." Derek said awkwardly.

"How long?" Meredith enquired.

"The night before me and Addison got married was the last time..."