fapturbate
Jerkin off.
Austin's sister is really hot. I'm going to fapturbate to her.
Fapturbate
Masturbating in a way that where your hand slaps and or slapping your scrotum while stroking down to make a smacking noise.
My friend and I had a fapturbating contest we wanted to see who could do it louder before teachers outside the bathroom could hear us. When we fapturbate our scrotums get so red from the smacking.