My family was recently invited to my brother’s wedding — my husband and I, our 21-year-old daughter, and our 18-year-old son. The only person excluded was our youngest son, who is 16, because the wedding was described as child-free. I called my brother to confirm this, since I’ve attended child-free weddings where teenagers were still welcome, and my son is mature, well-behaved, and wouldn’t need supervision like a small child.

My brother apologized and explained that he couldn’t make exceptions because some of his friends have very young children, and he didn’t want to appear unfair by allowing my son to attend. I understood completely — I even had a child-free wedding myself, before I had kids. Since my brother has two children from a previous marriage who are 16 and 17, and my sister has children aged 13 and 15, I assumed none of them would be invited either.

The wedding is taking place in another country, and we’re flying out for the weekend. My 16-year-old was understandably hurt, especially since he’s very close to my brother, and I wasn’t comfortable leaving him home alone. So I planned for him and his cousins to spend the wedding night at the hotel — using the pool, ordering room service, and having a fun evening together. The next day, we’d all explore the city so he wouldn’t feel excluded.

When I told my brother about this plan, he thought it was a great idea. However, when I mentioned it to my sister, she was shocked — because her children had been invited, and she had no idea the wedding was supposed to be child-free. She checked with my brother, who told her the rule was actually 13 and up, which meant her kids were included.

My sister and I then confronted my brother together. He admitted that my son was the only under-18 member of the immediate family who hadn’t been invited — but he refused to explain why, no matter how much we pressed him.

As a result, my sister and I both decided not to attend. She adores my son and was furious on his behalf. Our mother has since called us, accusing us of being childish and unsupportive. My brother’s fiancée is also upset, saying my brother is heartbroken and that my son was excluded “for a good reason,” though she won’t say what that reason is. My brother-in-law is angry as well and blames me for my sister’s absence.

Now I’m starting to feel guilty and wonder if I should have just stayed quiet and gone along with it. But I can’t help asking — was I wrong?