tldr - I think my SILs intentionally left me out of matching family outfits on our trip & got upset; they said it was all in my head. AITA?

I just got back from a family trip & created this account to figure out if I am the A*** because I can't tell anymore.

My husband and I have been married for aprrox. 15 years, and his family has a history of excluding me and one of our kids from events. This year, we went on an all inclusive trip that a friend also booked.

One SIL loves matching outfits, so we picked out stuff for the kids including a swimsuit and a shirt. I asked if adults were matching and was told no. On the first day, they showed up with their families in matching outfits with one another. They shrugged it off and said they just forgot to tell me.

The next day, after breakfast, my SILs disappeared & the kids followed. We went to the meeting place but they weren’t there and we couldn’t get any response to messages. When they returned, they were dismissive & said the kids followed them but didn’t address the messages; they left again a short while later to eat lunch without us. We rejoined them later, but it was clear we were not included in their plans. They showed up for our dinner plans in coordinated outfits/colors again and, again, we did not get the memo.

By the third day, everyone, including the friends kids, were in coordinated colors except my family. When I confronted my SILs, they denied anything was done intentionally and said I was overthinking things and moving too slowly for the group. They also said I was making everyone miserable and that I was aggressive for expressing my hurt feelings.

The rest of the trip was awkward. I felt excluded and hurt, and now I fear there will be fallout with my MIL and the whole family. AITA for feeling upset and confronting them?