When we were first married. I had to go out of town on business, and I was gone for several weeks. During that time, My wife went to a movie with my kid brother (he was 16 at the time). They ended up making out in his car when he took her home and he forced her to suck him off. She let it happen, sucking him to completion. She felt really guilty about it and told on herself to me. Instead of being angry (even though I felt some jealousy) I told her not to let him know I was aware of it, I told Teresa to go ahead and play with him if he goes after her again. 

It was not long until he did just that. Teresa was home alone and he stopped by the house. He ended up taking it all the way. Getting my wife to make out with him on the couch, Finally ending up fucking her. She was trying to protest, to tell him no, but he took her by force, not taking no for an answer. He had no idea that I knew about anything and that Teresa actually had permission to fuck him. She allowed it to seem like force to him, which she said seemed to really get him off. He ended up screwing her several times over that evening, with no protection.  He fucked her another time a few months after that, but none since, as far as i know.

From the timing, I think there is a real possibility that our daughter is his. So my daughter may be my neice. I raised her as our own because DNA is close enough with brothers to not really matter. She looks like him, but that can happen even if she is from my sperm. I still wonder at times if our daughter is really my neice, and my wife has a child with my brother.