I just found out my husband received oral from his cousin when they were teens

I've been married to my husband for 6 years and been together since 2002 (16 years). I just found out that when when he was around 17, he made his 13/14 year old cousin give him a blow job. He says she wanted it and she says she only did it so he would leave her alone. She says it happened more than once. She got pregnant around 15 years and she's known for being very sexually active at such young age and with different guys, she has a bad reputation and according to her sister, she is now trying to change her life for her 4 kids. When I met my husband, they had a good cousin relationship, they would only see each other at party gatherings and everything seemed normal. I never saw any disgust towards him from her, it looked like she actually loved his cousin in a cousin way. 2 years ago we found out her father had molested one of my husband's nieces for quite some time and took him to court and he eventually got arrested. Ever since, my husband and her have never spoken again or seeing each other, this situation broke the family apart. His cousin now brought this up after almost 18/19 years and it seems strange that she never said anything when the situation with her father was taking place, I would've said something. I remember when I was that young and said NO to innapropriate behavior from older guys. I don't know if she's doing all this to take revenge for what my husband's sister did to her father or what? I know all this because his cousin's older sister told me and I'm yet waiting to confront my husband about it. He hasn't said anything to me for fear of losing me I'm assuming or he's ashamed about it. I don't know what her cousin's intentions are but I feel very weird inside. I don't know what to do... should I throw all these years away and leave my husband? He's a great man and I know for a fact he's not a pedophile and all this happened years ago in his teen years and I know we all make mistakes when young and can't change them unfortunately. I love my husband very much and I know he's not a bad guy, it was just a bad choice.