Refuse politely

"ummm i don't know sarah... I dont wanna really skip all class, thanks for the offer we could have fun another time maybe?"

As you talk Sarah's face turns into a frown at first but your last word turned it into a happy hopeful face

"Sure! I could still give you a ride to university then I'll go home, maybe I'd catch up to you later on" she smirks a bit "i could miss your ass quickly"

"Heyyyyyy shut up" you blush and gently punch her shoulder "you're such a tease!"

"Oh you haven't seen anything" she grins "just wait till we get to sit together in class.. I'll show you what teasing really is"

She laughs and keeps driving till you make it there almost in time

"You gotta hurry up naughty boy, you don't have much time before class starts"

You hop off the car and nod smiling "alright, thanks for the ride and ummm... The other thing..."

"Oh you're very welcome" she grins before driving away.

As you finally get on your feet you notice how sore your ass is after the rough sex you had with her and try to walk in a normal way so you won't attract any attention but you can notice that eyes are already staring at you from some girls but you just shake it off and quickly make your way to your first class.