That boobs, and no bulge. Dick are magically appear when erected, like that from bible black, imo more qualified as futa than trap. Even in other imageset they still labeled as otoko no ko despite their physical appearance say otherwise.
It's not backward, it's a kappa. He says he wants something,her*semen,she* gives consent, then she ejaculates with the backward hand that attaches at all times; here the challenge was not interrupted and carried on.