It's long and not relevant and I'm on my phone, but here you go. My "uncle" (he's not, but that's what I called him as a kid) was married, she cheated, he abandoned his three kids and "remarried" (there was no divorce, thus no marriage, but there are photos as if they married--my family is weird! His second kids don't know the wedding was a sham, but everyone else does, ugh).
New family doesn't know about old family, old family believes he left them for the new family, not because of the cheating because he's too much of a macho jerk (no, really, that's his excuse when I straight up asked, though, he phrased it differently) to admit his first wife cheated.
So, he's got one group of kids he abandoned and never paid child support for (they look just like him, and dna testing wasn't available when they were kids, he believes them to be his, just wanted to punish their mom, who by all accounts was a great mother--yes, terrible wife, but great mom). They hate him, and reasonably so based on what they know. Then, he's got the second group of kids to whom he was a controlling, obsessive, angry father, who pretty regularly stalked their mother and refused to let her work, so they were very poor (It's hard to keep a job when you up and leave at random times to go check up on your wife--by all accounts this behavior didn't happen in his first marriage which is possible--paranoia does weird things to the brain). Those kids also hate him.
He's actually not a terrible person. He just royally messed up two families all because he was so furious about the affair and what it "said about him." Instead of focusing on being a decent dad to all his kids.
Families are weird and they do hurtful shit to each other, but sometimes they do it for Reasons, and I think those are worth knowing. Not to necessarily rebuild the relationship, but because I think truth is always better known than hidden. I think all his kids would feel better about themselves if they knew the whole story, alas, he continues to be adamant no one can know and everyone's afraid to cross him "after what he's been through."