Damn, y'all...
I have a stupid idea, lemme tell u bout it.
What if... Incubuses and Succubuses weren't really born sexual but taught to be sexual?? Like, a newbie was lead by a senior to a room where they'd be trained by having coitus. Then when that newbie becomes a senior, the demon that trained them could be their best friend in the future. As in when this one human ding dong ditched one of them, the other curses the human to have polio or something.