A Cum Dumpster is a woman or group of that only serve society by playing a key role of removing cum from the environment. This can be done by anal, vaginal, oral, ear, belly button, hand (as long as hand is then licked afterwards) intercourse. This does not apply to gays because gays do not exist, they are a government conspiracy. See Jenna Jameson.
Jeff was tired of useing lotion and his gym sock, so he called neighborhood whore Liz Smith who is a well known Cum Dumpster.