User blog comment:Leadp1pe/Is a Succubus Faithful?/@comment-24851346-20140618134046

Well the Demon Lord is a Succubus, but she's a monogamist, and devoted to her husband. I think a Monster Girl is willing to starve herself for a guy she likes, and if she's a succubus, or other Monster, I don't think the guy will really be able to say no, either she'll pin him down or hypnotize him.

Also I figure if a girl has feelings for a guy, it turns pretty obssessive if they turn into a succubus, look up Wilmarina.