this may actually have more to do with incest triggering stress than the sexuality itself, I've gotten a similar result with complete consent, sister of protag, hermaphrodite (as I understand how the hermaphrodite sexuality works the actual stat is mostly irrelevant as long as one partner isn't one, correct me if I'm wrong).
With Hermaphrodites/Futa, they count as both man and woman for the purposes of determining same-sex. It essentially means that Futa will likely be at least bi, as most actions will be same-sex to them, and most participants with them will score higher for bi or gay (Scale 3-6).
It may not be the cleanest way of handling it, but the way I figure it you have do be somewhat comfortable handling both parts to enjoy a Futa, eh?
