Get him on all fours

You push Brian down, and he quickly understands what you want as he gets on his hands and knees, staring at the cum he just splattered on the window.

"Show me how good it is, Brian," you command as you mount his round ass and drive your cock into his waiting asshole.

Brian begins moaning again, and starts to lick his own cum off the window in front of him. You thrust harder, and begin to smack his ass as you feel yourself closer to orgasm.

"Fuck yeah, smack that ass. Harder!" Brian says as you lay into him, leaving a large red mark on his massive ass.

"Fuck, Brian, I'm close. Finish up your cum, because you're going to get more"

As he licks the window clean, Brian pulls you out to face you on his knees.