When your dick has been slopping around in a lot of pussy in one day.
Don - man how many bitches have you banged today?
Ed- I only banged Diane and Veronica today and maybe Tammy!
Don - You got one hell of a slopstick going on!
Paul - Well I got more of slopstick than you, I banged all them and then the cleaning chick in the restroom after that.