The reproductive system (gender neutral).

Generic term for the bars of a jail cell

The act of purposefully stopping up your toilet so that the plumber will come to your house and unclog it.

Wearing one's pants so low as to display one's asscrack. Derived from the state of many a fat plumber's pants.

Bhe act of saving a life when a person is drowning or choking by repetitively thrusting one's penis in and out of the person's throat. The thrusting creates a plumbing effect that forces the obstruction to move up the throat. This action is in no way sexual; it should only be used during times of grave danger.

(verb) Very deep anal penetration
Deep-sea plumbing: Anal penetration over 10 inches

Plumbing is a sexual act involving a man and a female. The aforementioned male pops his penis in the girl's vagina, lubricating her ring, tickling and widening the said orifice. When that there hole is at maximum size, the man pops the scrotum and both balls in that bottomless pit of love.