FI has 3 cousins (2 boys and a girl adults and married) on his moms side (he has 4 other cousins on that side too) we do not see them ever. Holidays are with the other aunts and uncles and cousins, but never are with the other aunt/uncle and kids. In the 4 years I've been with FI Ive met them once 2 years ago. Also, I was told I didn't need to invite them to the wedding because they have a "rule" in the family the "kids" don't get invited, but I did because they are family end of discussion.So when I did my shower addresses, I didn't invite those cousins, the one is actual cousin the other two are cousin-in-laws I dont know them and because of the "above rule" I didn't think it was a problem. Before hand (knew nothing till now) FMIL told my mom that the cousins bought gifts prior because they thought they would be invited so my mom said "oh it must have been an oversight, I can send an invite" FMIL said no I will just tell them. Yesterday they didn't show because they felt weird because they didn't get an invite. FMIL never told my mom (but thats a whole other story) so my mom was confused, and told me what happened.Now my question is, next month I am going to see all these girls at a baby shower for one of them (got the invite AFTER my shower invites went out as well as the entire family was shocked that me fsils fcousins were invited). Do I send them an apology before or apologize at the shower? Do I just ignore it and hide behind my FSIL the entire day lol. I don't even know how to feel about this, all my mom kept on saying was "well fmil said they got STD" I was like yea, for the wedding not my intimate close family/friends shower.WWYD?