1. To use the tongue to suck and enter the asshole of a partner before anal intercourse. The tongue is often repeatedly jabbed at the asshole to relax and open the ass ring.
2. To use the tongue to suck and enter the asshole of a partner after anal intercourse. Used as a method of extraction of semen and other fluids from the rectum. See felch.
Tom tongue fucked his buddy's tangy asshole and reclaimed his load of cum.
When your bag of coke or ket is almost completely empty so you have no other choice but to stick your tongue into that bag and wiggle it around to remove all the residue. Never waste your drugs.