The title says it all. And don't it just harken back to like 1998 and the golden era of A.S.S.(M.)? I did do a print-out and pen mark-up of this one. So enjoy a boy discovering his older sister. Under unusual circumstances!
Allie can't have any more babies, even though she and husband John would like another. In a moment of delight as he fills her pussy, she has the idea of getting her son to fuck her eldest daughter pregnant. Perhaps, she reasons, if she were to get him addicted to bareback sex and then somehow contrived to get him up close and personal with Danni, maybe nature would take its course? There's another member of the family, Rachel, who hasn't yet reached menarche, as far as anyone knows...