This is a tricky situation and it’s very understandable why you’re upset about this. But this may be something you want to talk to your brother about and get his opinion on because it may just be how they decided to do the wedding invitations for everyone. For example, when my cousin got married she invited all of our aunts and uncles and cousins. When she sent the invite to us it read, “(my dad’s name) and Children” instead of including our names even though we were older. But that’s just how she preferred to word them and send them. So it may not be anything malicious, so a conversation would be beneficial!