That “whopping”, smacking sound made by a dude’s balls and ballsack as it smacks repeatedly against a girl’s taint or butt cheeks during some vigorous sex. Position, intensity and type of penetration (vaginal or anal) vary the level of whop.
Whopping may also occur during a serious session of skull fucking oral with the smacking of the sack against the chin or throat.
My nuts are sore from ball whopping Rachel last night.
I think my mom could here the ball whopping coming from my room. I muzzled my girl’s moans by stuffing her panties in her mouth but I could do nothing about the beating of my mansack against her ass.