My husband (M47) has thrown me(F42) under the bus to make our son (M17) happy and I’m livid

My family has been having issues with my husband’s older brother (M50s) for decades. Literally since we were all young and I know exactly why the relationship is as it is. We are just too far gone to fix it. It has been decades since we were face to face with them but we have been informed of their activities through other family members. The last my son heard of his uncle was that he became homeless. <br><br>My son has been asking to find his uncle for the last four years. He sent him a message last year and uncle didn’t respond but my husband did find out that he has been rehomed and seems to be doing quite well. Son went completely silent when we told him and seemed fine. <br><br>We didn’t hear anything about the uncle issue til the day my son turned 17. He had plans for us to go camping in our national park and my husband and I decided to tag along.<br><br>All was well on the trip until he reached his final destination. It was uncle’s house. We told him that he had no right to do this and that we didn’t want to see his uncle. He said that he wanted to meet his cousin (M15) and didn’t care if we didn’t want to see uncle but said that he will not turn back. We drove for four hours to get here and I was too tired to argue with him any more so I relented and I told him that I will meet his uncle. <br><br>We went to the door and before knocking said that he has been wanting to meet his uncle for four years and didn’t care if we didn’t want to be here but he wasn’t leaving. I told him that I wasn’t comfortable with this and to turn back but he didn’t so here I am on his uncle’s door.<br><br>Uncle answered the door and I told him that I wasn’t happy to see him and that I didn’t want to be there. He asked why I was there and I told him that my son wanted to meet him and I didn’t have a choice. <br><br>We were greeted by his daughter (F15) and I immediately noticed that the niece looked like our son’s ex girlfriend (F16) whom we had a fight with last year. The girl was a cheeky thing who liked to wind us up by being a little naughty with my son then walking away like the cocky little girl she was. When we told her to stop the behaviour, she told us that she was just playing around. <br><br>When my son asked my niece if she knew his ex girlfriend, she said that the girl looked familiar but she couldn’t place her. My son pulled out a picture of his ex on his phone and she was shocked to learn that it was in fact her. The girl was my husband’s brother’s daughter and she was the result of an affair he had with my son’s ex girlfriend’s mother(F40) and the niece was only a few months younger than my son’s ex girlfriend. <br><br>I’m livid with my husband. He KNEW about the affair and what it meant for the niece’s birth. The reason why my niece looks like my son’s ex girlfriend is because they are sisters but he is the dad of one and not the other. <br><br>My son and niece were playing around and getting to know each other and my husband told them that they should get a DNA test once they get home just to confirm that they are in fact siblings. The two kids were obviously confused and asked my husband what he meant by that. He told them that he just wanted to confirm that they are truly siblings and that he was just curious that’s all. <br><br>I asked what he meant and he said that the niece could have been the ex girlfriend’s sister but from a different dad so they would technically be half sisters. The niece immediately broke down crying and then I understood what my husband said. He was telling them that my son could have been the product of an affair that I had with his brother and the reason why we have been arguing for so long is because my husband caught me cheating and the reason why we don’t talk anymore is because my husband confronted his brother and his brother told him to mind his own business. <br><br>My son then started yelling at me, asking me if I cheated on dad and I denied it. He then asked his dad who told him yes and said that the reason why we don’t talk to his uncle anymore is because his dad caught me having an affair with his uncle and the reason why we moved away is because his dad threatened to castrate his uncle and I was too embarrassed to stay in our old town after everyone found out what I did. <br><br>I tried to tell him that it was a lie but he didn’t believe me. I told him that if I had an affair with his uncle then the niece would look like him instead of his ex girlfriend. My son told me that it doesn’t matter and that he hates me for cheating. I told him that I didn’t cheat and that if I did, I would’ve been divorced a long time ago. <br><br>We left but my husband stayed for god knows what reason. My son didn’t want to come home and told me to go and fuck my lover since I was already fucking his uncle. I drove home alone and when my husband got home he said that he was just trying to make our son happy and that the past is in the past. <br><br>I’m fucking fuming that he threw me under the bus to make his son happy.