As you're tonguing a she-male's gooch
(or grundle)on the dryer, maneuver your body around for anal penetration, and while doing so, administer a hefty slap to his/her testicles, put the dryer on fast, and ride it out.
Works best at laundromat, or your neighbors garage.
Billy: So I was giving the Louisiana Bullride to Pat yesterday, but I forgot to put a quarter in the dryer!
Billy: Yea, Pat was super pissed that it's balls weren't swinging like they should
Jeffy: You mean, no thwapping?