Typically occurs when a girl is going down on you, and she inadvertently gags while sucking on your balls. While gagging, her gag reflex causes her to regurgitate and throw up on your package as you cum; and in the process, cannot stop cumming during ejaculation.
DB 1: "So what happened last night with that Biddy you took home from Libby's?"
DB 2: "Well, she started polishing my knob, then started going off on my plumbs."
DB 1: "And...."
DB 2: "...and I basically ended up with the ole' Newmarket Jambalaya......."
DB 1: "Oh Shit!. Hey man, same thing happened to me last week. No harm done."