I am really close with my FI's father's side of his family even though they live all over the us. Even though I have tried to create a relationship, I am still practially strangers with his mother's side of the family that lives locally. My FI's doesn't know his mother's side well either, in fact he can't remember most of them existing his is always getting the wrong number of kids or names. In fact he can only name two of his cousins' names.
Is it wrong of me to want to exclude his mother's side? My MIL says I have to invite them because all of his cousins all got married when my FI was in jr. high he was invited to all their weddings but honestly, I don't see the attachement because it was so long ago and we weren't invited as a couple (at tweleve we had never met.) If you invite a tweleve year old to your wedding that gives you an instant invite to his wedding over fifteen years later?