Face pressed between her cheeks
Lesbian rimming puts a tongue on the ass and keeps it there. Both hands hold the cheeks apart, the face goes in close, and the woman receiving arches her back to give it more room. It works for an anatomical reason: the skin around the anus is dense with nerve endings, and a wet tongue reaches all of it with no lube and no stretching.
Keeping her open and the tongue busy
Kneeling on all fours with the ass raised is the most open position, and a cushion under the pelvis lifts a woman lying face down to the same height. Seated backward over her partner's mouth, a woman controls the pressure herself, the reverse form of facesitting that puts the tongue on her ass instead of her pussy. Broad, flat licks across the whole crack warm things up, and a stiffened tongue pushed inside, known as tongue-fucking, is the more intense version. Fingers or a slim toy can follow the tongue, which is where lesbian rimming crosses into anal play between women. A shower beforehand is simple courtesy, and a dental dam is the safer-sex option. A spare hand belongs between her legs, because pressure in front and a tongue behind build on each other.
