Masturbation.
In other words:
Choking the chicken Choking the monkey wacking off
jerking off
shaking hands with man's best friend teasing the weasel
Dude, we all know that last night you did the five finger knuckle shuffle on the one-eyed, blue-veined, purple-headed, custard-chucking, salty yogurt slinger.
boner erection
pitching a tent
sporting a wood
icicles formed
the march is on
stiffy
mr. mortis
rigor mortis has set in
flesh rocket
jack's magic beanstalk
tall tommy
mushroom on a stick and, uh, pedro
varsity blues classic scene, purple headed yogurt slinger is the final example prior to pedro.