The act in which a male ejaculates in their partners mouth causing it to fill up. The man then smacks his penis on the mouth causing hot sticky cum to spray out like a hot air balloon.
Friend #1: dude I was hot air ballooning my gf last night.
Friend #2: damn I really want to try that with mine.
When you’re eating ass, and the receiver farts hot air in your mouth and puffs your cheeks like a balloon
“Man I was eating her ass real good the other day and she hot air ballooned me, it was weird but I think I liked it, I might be into hot air ballooning”