Have her walk home alone.

"You're trembling." You say. "But I'm guessing that you're not cold."

"It's a bit cold I guess but I'm just too pumped to really notice." She says.

"Are you ready to go back home?" You ask, putting up a warm smile.

"Can we?" Her face is all relief. "I'll totally fuck your brain out when we get back I promise." She giggles.

"We'll go home on one condition." You say as your smile turns devious. Carrie turns a bit pale in dread. Your hart is racing with excitement. "I give you the spare key, we go home separately, I'll take a slightly longer route and once I get home I'll put the chain lock on the front door."

"What if I say no?" She asks as she bites her lip.

"I guess the night is still young. I'll go to the bar, I'll see you in a few hours. Bye."

"Wait!" She yells as you turn around. You turn back to face her and smile. "Ok, let's head home than. Give me that key."

The two of you split ways and you're off for a nice walk way around the park, but you're not gonna give her too much of a headstart.

Meanwhile she's completely naked, alone in the park, facing the task of getting herself home before you do.