Any sexual activity that results in skin clapping and flopping around. Primarily but not limited to balls banging against ass.
Do hear that? Sounds like they are beatin cheeks in the room next door.
Man that Chet fella is a real cheek beater, everytime I talk to him I can hear beating cheeks.
having sex, the sound when u are serving up a girl from behind
Yo, i was beating those cheeks yesterday