I F32 found out my boyfriend M31 father M58 is in jail for rape.

I F32 found out my boyfriend M31 of 7 months father was in prison for raping his own sister (my bd auntie) as a child when he was 14 and she was 9. My boyfriend told me his father lived in another country but this all came out one night when he was drunk. He believes his father is innocent. I dont know how I feel about his lying to me for months or about the situation. Would you stay in the relationship?

Edit: he said the sister (my boyfriends auntie) made up the story because she was left out of the will. She made the accusations 6 years after the grandmother died. It wasn't much money, maybe 5k. She had to travel from the US (where she's been living most of her life) to Ireland for the trail. It was actually held outdoors because of covjd. He got 4 years in prison. She chose to remain anonymous.

Edit: I dont know how relevant this is but my bf mother abandoned them when he was 8. He saw her once in his lift after that. When his dad went to prison his dads girlfriend stole his dads car sold is and moved back to her home country.

Edit: okay here is where it gets even more crazy. Two of my bf uncles also accused my bf father and another uncle of raping them also when they were kids. First trail was a hung jury. Second trial they were found not guilty.