You decide to go out

You get your shorts back on, wet cum still leaking out of your ass. "I really need to wash the shorts when I get home", you think to yourself.

With Marvin still sleeping you sneak out of his van. Even though there's no real reason to hurry, you still feel a need to get as much distance to Marvin's van as possible, so you break to run. Your sore ass and wet cum ruining your shorts makes running a bit awkward experience.

You are almost at the opposite end of the parking lot, when you hear car starting behind you. You turn around to see Marvin's campervan exiting the lot. You realize that it was supposed to be your ride home.

You take a long look around. Even though you aren't completely familiar with the area you're in, you recognize the park and know that you could walk home through it. It'd be a long walk, but it's doable. You could also go check out those other cars in the lot. Now that you're closer to them you can see that there actually seems to be someone inside one of them. Maybe he could give you a ride home?