1.

The first time Derek meets Stiles and Scott is in the middle of the night. He's heading back to the Gryffindor tower, having just parted ways with Jen Blake, lost in thought - how on earth he would be able to avoid her for the rest of the year? He adjusts his Prefect badge with a guilty sigh, and he's almost there - so ready to go to sleep - when some douchebag barrels into him from a hidden side passage.

"Fuck!" Derek loses his balance and finds himself lying face up on the floor with some kid on top of him. The kid is laughing hysterically and flailing his limbs. Another kid hovers in the shadows, whispering "Oh my God, dude, we are busted!"

A few moments of fumbling follow, and by the end of it, Derek is fuming.

"I am a Prefect," he hisses at them, pulling out his wand and shining a light on their faces. "What are you doing? I'm reporting you first thing this morning."

They're fourth-years, he realises, and it's not the first time he's seen them - they were both at the Hufflepuff Quidditch try-outs the other day (Derek makes an effort to go to all the other team try-outs to scope out the competition). The one with the floppy fringe has actually been on the Hufflepuff team for at least a year. It makes Derek even angrier - Hufflepuff always manages to beat his team for some reason. Must be something to do with Hufflepuffs being such team players. Whatever.

"Who are you?" he demands, glaring at them.

"Stiles Stilinski and Scott McCall, sir," the tall, lanky one gives a mocking salute before looking Derek up and down with a skeptical expression on his face. "Aaaaand I don't think you'll be reporting us, since it's pretty obvious you've been up to some shenanigans tonight - she likes a man with a badge, huh?"

The kid gives an exaggerated wink and a pointed look at Derek's untucked shirt, tie draped over his shoulder, hair mussed up and - oh God, she'd been wearing that fucking bright red lipstick.

He feel himself blush and mutters Nox, hoping they don't catch a glimpse of it. Jennifer Blake? More like Jennifer mistake. Hah. He deliberately pushes past Stiles and Scott, barely resisting sending a curse their way by imagining his big, plush red bed just waiting for him…

He falls asleep as soon as his head hits the pillow and dreams of a snarky boy looking him up and down, winking, then leaving red lipstick marks all over his body.

Stiles raises his eyebrows at Scott, letting his breath whoosh out as Derek Hale (super-hot Gryffindor Prefect, Quidditch Captain and total grump) stomps off down the corridor.

"That was close!" Scott whispers, with that stupid adorable half-grin on his face. "Imagine if he found out what we did to the Coach's office… we'd be screwed." He whistles. Stiles grins back at him and claps his shoulder as they head back to the Hufflepuff common room. Slowly, this time. The last thing they need is to run into another Prefect.

When Stiles goes to bed he amuses his overactive mind by imagining how the Coach would react to all the furniture in his office falling apart as soon as he walks in the door. But when he goes to sleep, an unusually grumpy fifth year student haunts his dreams...