Generally, a sexual position where each partner has the other's crotch in their face. Fellatio and/or cunnilingus are often performed in this position (often mutually). May also more loosely apply in situations like Danbooru post #5734472, where the focus is not the groin but the positioning is very close.
This position is possible regardless of the type of pairing (yaoi, yuri, hetero, etc.).
