Found out that my new stepmom is my moms former mistress

My parents divorced 6 years ago. My dad was the one who cheated and the one who filed for divorce. We found out later that he was cheating on my mom for over 13 years and in that time he had 2 children that he recognizes and 2 more that he doesn’t (but that everyone knows are his).<br><br>He married his last mistress and my siblings and I are not allowed (by him) to see his younger kids.<br><br>Back to my mom, Constance. Mom was well aware of my dad’s cheating and it was basically something that she had accepted, as long as her “family” was together and had a home. <br><br>After dad left, mom raised my siblings and I alone. After 3 years, my mom met a new guy and she seemed happy. We met him a couple of months later. His name is Jim, a divorced guy with 3 kids of his own, and well, my siblings and I didn’t really like him in the beginning. He was just too lively and obnoxious for our taste, but mom was happy.<br><br>They dated for 3 years, and around a year ago they got married. We were not really happy about it, neither were his children. They are not too fond of mom, and even less of us. Jim’s children are all adults just like us, and one of them is married. <br><br>We found out 6 months ago that mom was pregnant. We were shocked because mom is in her mid 40s, and she had a rough pregnancy with my youngest brother, who was born 21 years ago. When mom told us, we were shocked. We knew that she and Jim were having a lot of sex, as well as fighting a lot, but we didn’t think that a baby would be the result. <br><br>Mom’s pregnancy has been very rough. She has heart problems, and she is due to have a heart surgery early next year. Her pregnancy hasn’t allowed her to have her heart surgery, so she has been suffering a lot. <br><br>Jim’s children were not happy with mom’s pregnancy. They didn’t want to have another sibling and they didn’t want her to procreate, especially considering her health. <br><br>Last week, we had Christmas dinner at Jim’s house. Mom didn’t go because she didn’t feel well and she needed to rest. The dinner was tense but it went well. Jim’s eldest son, Scott, approached me in private, and in a very serious tone told me that mom wasn’t who I thought she was. I was confused and asked him what he meant. He showed me pictures of mom and his father having sex in her bed, and other pictures of them together in a hotel room, back in 2006. He told me that back in the day, his father threatened to divorce his mom because of mom, but his “selfish father” didn’t, because his mother was too young and had 3 babies and he ended the affair and promised not to see her again.<br><br>He then showed me a series of text messages of mom and his father, which supposedly happened in 2011, but it could’ve been anytime that they did it. The texts were from mom to his father, asking him why he didn’t call her back, asking him why they couldn’t continue their affair, etc. He gave me a copy of the texts and pictures.<br><br>I’m Constance’s daughter. I just can’t believe it. I feel bad because this would hurt my siblings and my brother who is going to be born in two months. I don’t know what to do with this information.