"Oooh fuck... I can't belive you broke that vial. There's no way my dad's not gonna know we were in here, and he's gonna be pissed when he sees me like this."
"Shit, I'm so sorry Marty. Maybe there's something around here that can change you back before he gets home..."
"Mmmm, no. There's no way we'll figure it out in time. Besides, there's no way I can concentrate in this body anyway. I feel so... distracted, ya know?"
"Yeah," Danny eyed Marty's new body up and down. "Me too."
They were all over eachother in an instant. Fortunately they had time to act on their teenage urges before Marty's dad got home. If they knew Marty was going to be stuck like this, they might have had a bit more patience, but it's fair to say that neither of them were thinking clearly at the time.