this is quite interesting.
people in danbooru think that all of them are boys.
people in gelbooru think that all of them are girls, and those with penis is futa.

My guess: there are 1 girl(the one without wings) and 2 boys there.
(I already changed the tags)

I just facepalmed. The two having sex are boys and the one to the left is a girl, I checked on the image packs.