[M4F] We are total strangers who will never see each other's faces. The only thing that you will know is that you're going to be pregnant by the end of it.
[F4M] For months, we have been sleeping together. Every night she hopes for you to impregnate and make your sister yours, but you've been hesitant. That's where a succubus, comes in to 'motive' you. (More in coments/post)