Derek was walking past Stile' room when he heard what sounded like moans.Angry at the thought of anyone touching his mate but him he ripped open the door to reveal Stiles jerking off on his bed.Stiles looked like a deer caught in head lights as Derek slammed the door behind him.

He yanked Stiles over his knee and began to gently caress his ass cheeks shifting from one to the other."Do you know why you're being punished love?" He asked causing the smaller male to whimper and shake his head.

"Verbal response baby~" He cooed as he delivered as sharp smack to the teen's ass.

"I-i don't know sir!" He whimpered and Derek looked satisfied with his answer.

"You were a naughty boy,touching yourself without permission." He spoke in a stern tone as he delivered another sharp slap to the boy's rear.

"Now be a good boy and count to twenty for me." He ordered softly if that was even possible.

"Yes sir." Stiles said with a blush as he started counting every time Derek spanked him.This went on until they reached twenty and he had visible hand prints on both of his ass cheeks.

"Good boy Stiles,you took your punishment so well baby~" He cooed and cradled the smaller male to his chest.