hard and fast

As soon as you shut the door, you pull her towards you. Ripping off her top as you go, "W-w-what are you??" she screams as you transform back into the demon form that you now feel most comfortable in. "My dear, I am an incubus, a pleasure demon, here to please you." Slowly you move nearer until your massive cock is at the entrance to her pussy.

As you ram it in, she screams until eventually the inevitable happens "Why can't I-I cum???!!!" As she says that, you unleash a torrent of demon seed in her tight pussy, filling her with the virus.