Sankaku Channel/urethra

The Urethra is on the pelvis in humans.

In males, the urethra carries both semen and urine out of the body, and is located inside the penis. It extends from inside the pelvis, all the way to the tip.

In females, the urethra is used only to carry urine out of the body, and is located in the vulva, above the vaginal opening.

The Urethra can also have objects pushed into it, as is part of the Urethra fetish, but this generally hurts a great deal, and generally gives no sexual pleasure to the victim.