Incubus
An Inccubus is the oposite of "Succubus".
While Succubus means "Lying under" Inccubus means lying over.
And Inccubus was once an man who refused to lie over a woman and was thereby punished.
While a Succubus was once a woman, but was punished by refusing to lie under.
An Inccubus rapes woman, while the succubus rapes men.

Origins:
A number of secular explanations have been offered for the origin of the incubus legends. They involve the medieval preoccupation with sin, especially sexual sins of women. Victims may have been experiencing waking dreams or sleep paralysis. Also, nocturnal arousal, orgasm or nocturnal emission could be explained by the idea of creatures causing an otherwise guilt-producing and self-conscious behavior. Alternatively, the influence of incubi could also have been invoked to explain otherwise "unexplainable" pregnancies out of wedlock.

Purported victims of incubi could have been the victims of sexual assault by a real person. Rapists may have attributed the rapes of sleeping women to demons in order to escape punishment. A friend or relative may have assaulted the victim in her sleep. The victims and, in some cases the clergy, may have found it easier to explain the attack as supernatural rather than confront the idea that the attack came from someone in a position of trust.
An Incubus visited me tonight