My little brother (23) is dating my ex wife (40) and I don't know how to feel or what to do

I am 38 and I got married in 2015, we had a daughter that was born in 2016. Unfortunately my wife was unfaithful to me on multiple occasions and I divorced her in 2019. We still share custody of our daughter and I am a nice co-parent, I don't speak ill of her to my daughter or anyone else. My ex wife is very close with my family, she's part of a groupchat with my mum, dad, sister, sister's husband, my cousins...etc.<br><br>We live in a southern European country and we have a big family plus we're all very closed due to the way we were raised. <br><br>All was good and I was in shock when my brother called me saying that he's afraid to tell nobody about his new relationship because it's with my ex wife and he was afraid of being judged. I told him I wasn't mad at him but he needs to tell our parents because I'd rather he does it before they find out. He is very persistent that they're in love and he didn't do it to be spiteful. I told him that it didn't matter, it's gross, they're 17 years apart and she's too old to be his girlfriend. It's also embarrassing, she's older than him by 17 years but to make matters worse she's 6 years older than his sister (my sister is 34) and she's 2 years younger than his mother... it's very shameful and embarrassing situation. <br><br>After all the drama was over, my brother told our parents and many of our cousins. Some were in favour, some not. Many argued that she's a very nice person and that we should be ok with the relationship. I am not ok with it and many others aren't either and I told my family and also my ex wife that I'm not gonna be ok with it until my niece turns 18 (2 years). I also made it very clear that I don't want my daughter to be around him while he's with my ex wife. He got very mad at me for that but I told him he has no right to get mad at me for not wanting my 8 years old daughter to be around his new girlfriend.<br><br>It's been 3 months since all of this was blow up to the family and it's been a living hell, many fights, many arguments, a lot of bad blood and many people taking sides. I don't know what to do, my brother didn't do anything wrong legally but it's in poor taste to be with your brother ex wife. My daughter is very confused and she's asking questions, she doesn't fully understand the situation but I don't want to give her any more information other than "your uncle is silly". <br><br>I don't know what to do, I'm hurt, I'm angry, I'm disappointed and I just feel like shit. I feel betrayed and I told all the family that but they just argue that my ex wife is a very nice person that everybody misses.<br><br>What should I do, how do I get out of this situation?