jise said: I don't think that's futanari. Someone else is thrusting his penis between Sayaka's butt crack. Will remove tag.
It is futa pixiv tags confirm it. Seki does only futa and yuri works also so its kinda easy to tell this was futa. He just doesn't make the other girl visible most of the time. So it ends up looking like a floating penis but its still futa.