jerk sock 

a sock that when guys are jerking off they (jizz) in it so it wont be on the curtains, carpet, bed or couch.

i had to flush my jerk sock because my mom came into the bathroom

jerk sock by symple jack January 10, 2009

jerk off sock 

A sock that placed on the penis to assist in masturbation.

Dave: dude, what's with that sock?
Jake: don't touch it! That's the jerk off sock.

jerk off sock by TheSpaceBaller November 24, 2015