AITAH for still keeping in contact with my ex's family?

(posting for my friend to get public opinion lol)

me (25,m) and my ex (24,f) recently broke up about 2 weeks ago. we've been together for 4 yrs+ and i rly thought we'd get married but due to some familial issues, we decided to end things off amicably. i'm really close to her family and they really like me so i feel sad that i won't be able to meet them as often now.

towards the end of the rs, when we were on a break to rethink our rs, she started hanging out very often with a guy (27 i think). even lying to me and her family that she was out with other people when she was really with him, until she got caught outside by my friend. anyways, we still ended things amicably because of familial issues.

few days after we officially ended things, i had a cruise trip with my boys. by chance, i met her family on the cruise and we hung out together (eating and gambling tgt lol). im quite close with her siblings (f, 12 and m, 23) and her mom so we talked about the relationship, and i told them my ex probably has a new bf, cause i saw her location at his house quite often. the brother was shocked cause she told the family that she was going out to celebrate a friend's home cafe. him being a self-righteous person, he was really angry for me. and the young sister who doesn't quit understand cheating or relationships yet was just really angry at my ex for having a new bf who isn't me. her mom straight up said she always thought my ex was cheating and always messaged her 脚踏两条船. the family was so in support of me they deliberately posted a story on IG of a group photo we took together so that my ex would see it.

fast forward few days after the cruise, i get a long angry text from her calling me childish and accusing me of trying to turn her family against her. she said i shouldn't have told her family about our relationship stuff, but genuinely i really like her family and the feeling's mutual. she didn't address or deny anything about the new guy being her bf though lol.

so AITAH for still keeping in contact with my ex's family?