Toxic family

So around 2 years ago, my parents/family and I stopped talked to part of my dads family, because they would all talk about us when we weren’t around/they’d go on vacation together, but one of my aunts would always be the one to say it to our faces, and she’s told my parents they’re shitty parents, and that my sister and I are losers and going no where in life, and that my younger brother is the only one that has “hope” even though I’m in school and work two jobs and my sister works. Not to mention they used to always put me down every family gathering because I had piercings, and would tell me I’d get no where and no one would love me because of them and would tell me why they hated my dyed red hair and would have “family meetings” during holidays to tell me how much of a terrible person I was. It used to make me feel like absolute shit and it still does even thinking about it. Well the aunt called and wants to “apologize” to my parents and they don’t seem to understand why I don’t want to see them again. They just keep telling me that I should be the “adult” and just forgive them and see them in the future. I’m an adult (I’m 26) so they can’t force me to go see that family, but is there a way I can explain to them why I don’t? I think my dad wants to accept their apology because understandably I think he misses them, because they’re the people he grew up with. But I’ve tried to explain that they’re toxic to me and I don’t feel like I should have to be around people that make me hate myself and make me want to cry. But they still think I should just be the “bigger person” and I literally don’t get why I should just allow people to be mean to me just because they’re family. Any tips would be nice. Thank you for taking the time to read