noun
facesitting
A sexual act where one person sits on the face of another. The term is explicit and used in adult contexts.
そのAVには顔面騎乗のシーンが含まれている。
That adult video includes a facesitting scene.
Compound of 顔面 (face) and 騎乗 (riding on horseback, mounting), literally 'face riding'. The term is a modern coinage for the sexual practice.