placing a finger or thumb into the orfice of an erect penis immediately before ejaculation, thus causing one large cumshot when the finger is removed and is known to make a "popping" sound
dude i was yankin one out the other night and decided to bop my top......... i shot a load that looked like a ball of wet paper towels
by papa j dizzle December 29, 2010
Get the bop my topmug.