Chihira-kun wa Maryoku ga Tarinai
Uhh dude finds out he's a succubus and needs to injest male fluids so he asks his best friend (who is secretly in love with him) to fuck him. And thus they fuck, and fall in love.
Uchi no Koakuma-kun
Ch. 6 Love this author's art. They make the characters look so smiley it's cute. Also don't be fooled by the cover (like I) it just looks like he has boobs. - Succubus, beautiful beings that seduce human males to consume their energy, they are the super idols of the devildom. Spica, a little demon who yearns to become a succubus, and so he breaks the law to travel to the human world alone. There he finds a human male to attack. He tries to steal his energy by having sex but the human thinks the whole situation... is just a dream?!
Ochinai Otoke
Can't rate, too short, but was good. - Incubus x succubus.
Baby, Sugar, Succubus