[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)
(F4M) Wait big bro, I feel it throbbing like crazy inside me! I'm not on the pill, and it's not a safe day! Pull out before you end up leaving millions of little incest sperm swimming in me!
[M4F] You've been getting a little baby crazy amd you hear through the grapevine that your neighbor's a pretty potent donor at the sperm Bank. But why bother with the bank when you can get it from the source?