A/N: My first stab at a Life With Derek fic. Warning: major angst alert! Sorry if it's ramble-y, but I wrote it at five in the morning and it just came out this way. Take it as a really long drabble or sorts, if you will. And good luck muddling through it. Please, if you like it or hate it, let me know with a review!

This is everything he wants, everything you want, so you don't fight it. Because for the first time in the year and a half you've been forced to coincide, you finally agree on something. And fuck the consequences.

Because with your back against the wall, legs wrapped around his waist, and lips smashed together, you don't really care if it's wrong or right or accepted or anything then what it is at this moment.

Two people who can't help but gravitate towards each other, because dammit, you're both young and you're both a mess of raging hormones and God, yes, right there.

He stops, but only to move to your neck. You're brain kicks into overdrive, and you hear footsteps from down stairs, the family is down there, your mom is down there, so you bite back the moan dancing in your mouth. You hold your lips tightly in a line, hoping that the blood coming from your now split tongue will keep the sounds at bay.

But then he nibbles on your throat and every inhibition screaming that this is wrong, wrong, wrong crumbles and you push him away only to grab his shirt by the collar and pull him to your room.

Or maybe it's his room.

You can't remember which door you both tumbled through, and you don't really know if the things you are stumbling on are his old, dirty clothes, or the ones you are stripping off right now.

He stays silent as you pull his shirt off, and as his hands glide over your stomach. You both stare at the other's mouth, not wanting to look at the eyes, betraying all of the randomness of the moment.

You don't want to see if he's just full of teenage lust, desire. You don't want to look up and see that this is nothing more to him than another fuck to nick into the bedpost. Casey McDonald, world's biggest prude, Derek Venturi's latest conquest.

And maybe, you don't want to see your own emotions reflected in his eyes. Because what a mess this would be if you both felt the same way, both wanted this for more than just today, now. Both wanted the sex, the kisses, the touches, the togetherness you would have longed for if it wasn't your stepbrother unclasping your bra. If it wasn't the boy whose family was your own and fuck everything is complicated so just focus on his zipper and pull down the pants and stop questioning it because answers ruin everything.

So you move in rhythm with him, all the steps a learned dance that both of you somehow know. You hold back the surprise as his movements soften, his kisses linger, and his gentleness floods the scene. Because this is Derek and he's not gentle, he doesn't linger, he isn't soft. But you stay with the flow, because this is what you want, right?

It's what you want and it's what he wants and the moaning from his bruised lips as your bodies covered in undergarments, but still too covered, grind against each other in an unvoiced need that screams Goddamnit, now! And then pull yourself from his grasping fingers as a voice floats from the bottom of the stairs (Casey! Derek! Dinner!) and watch helplessly as his eyes clear and his face hardens and his voice stays missing.

His finger points to the door as his other hand thrashes your shirt at you. You're thankful at that moment that he only unclasped the bra and didn't take it off, because if this situation could be any more awkward, it would be you standing half naked in front of your stepbrother.

But the situation is awkward, because you just nearly had sex with Derek and now you're frozen to your spot, the proverbial deer, Derek the headlights, and you still can't find your voice to say something appropriate to the whole scene.

So he goes first.

"Get out."

It's harsh and confusion is building inside of you but understanding fights its way to the top. And so you nod stupidly, still unable to form words and thoughts, let alone a sentence to respond, and realize for an instant that you are, indeed, in his room.

And God, is it a mess.

So you leave finally. And he doesn't move to stop you, though a part of you wishes he would to justify to yourself that you're not an idiot. But he doesn't and you know he won't, because he doesn't care and you shouldn't and now you're alone.

Dinner isn't awkward, he won't let it be. He snaps insults at you (Slow down there, Case. You don't exercise that much). And you let them slide because you still can't find your words. No one questions it, because yesterday you were crying over Max and now you're silent and brooding and they'll take that over sniffling, messy Casey.

And then you're in bed and the moon is out and the family is sleeping but worry and guilt and shame won't let you close your eyes.

That's when you hear your door creak open and the footfalls of someone you hope it isn't because everything is still confusing and you don't think you can handle his harsh words again.

But he doesn't speak and so you don't either. And in the moonlight, in the house that your parents bought together, you fuck and it's harsh and urgent and desperate. He's not gentle and you are surprised though you shouldn't be. His touches aren't soft and you're sure they're painting potential brown an purple bruises. But you don't care anymore, because he doesn't care and you don't want to hurt anymore. So apathetic pleasure overwhelms you as you call out his name and see his smirk in the dim light and feel every ounce of self-respect you once had shrink into nothing with his last thrust.

And silence once again engulfs you and you're both panting and two words finally find their way back to you and him but this time you're saying them.

"Get out."

It isn't harsh, or cruel like his were earlier, but pleading, because you hurt and you want to cry but you don't want him to see you like that. It's breaking on the last 't' and you find that your body is reacting before his and you can't stop yourself so you let a tear slip and watch as his eyes clear and his face softens and then his own words are falling out.

"I'm sorry."

And you believe him, because his finger slides against your cheek and it's finally gentle and nothing is stopping it. So you settle back into the mattress, still warm and smelling of sex and sweat, and let his arms circle around you as the sobs finally take over. And when they subside and you both have no more words to say, you let your body relax and notice his breathing is evening out and soon it will just be you and the shame and guilt.

And in the morning, when you wake up, you aren't surprised to find that you're alone.