I want to begin this story by stating that I am in an open marriage and everything detailed here is completely consensual.
I fuck my sister-in-law, probably more frequently than I do my own wife.
She is my wife’s half sister, they share mothers, and luckily for me she does not find our sexual relationship to be off putting at all. She’s even confessed being turned on by it, but that she would never want to watch us or join. I completely understand that.
It all began when she moved in with us. My mother in law is extremely religious, culitishly so, and her extreme religious fervor has driven all of her daughters off. I will call her Lynn here. Lynn is the youngest and last of the three sisters to leave the nest with a bad taste in her mouth and a desire to be naughty and rebellious.
Lynn is 25 now; she moved in three years ago. We enjoy having her with us for the obvious economic advantage it provides, and she is helpful around the house as well. We are less stressed having her help, and of course, I am less stressed because her and I enjoy a healthy sexual relationship.