My wife's niece
I had s** with my 19 year old niece on my wife's side(no blood relation) for a month. We had s** over 20 times, I came in her each time hoping that I would knock her up. I lied to her and told her I had a vasectomy and couldn't make any more babies, I actually did get a vasectomy 2 months after the affair ended. We both enjoyed the s**, my wife has never found out. In fact I had submitted to a polygraph to prove to my wife I hadn't had any affairs and I beat it.