When a passing a joint around, some drunk stoned dumb fuck drools all over the joint, making it wet. At which point the next person in line gets a wet joint, as if a nigger was sucking on it before him with his niggerlips.
"Steve is not invited to smoke out with us anymore, 'cause last time that dumb ass niggerlipped the joint!!"
The act of putting an excessive amount of a your lips onto an object that is being smoked by a group, coating the object in spit, making it gross for the next person