Before my fiance and I "finalized" our guest list, we both agreed that we were going to keep it to 21 and over with the exception of the few children in the bridal party (leaving the decision to their parents whether they wanted them to stay or not). While I did not want to have a lot of kids running around, I ultimately left the decision to my fiance as he has 13 nieces and nephews; he had the same feeling as me. However, I have 3 aunts/uncles flying in from Georgia and Florida to be home for my wedding, and all have children. It has been "strongly suggested" that I invite my cousins since my aunts and uncles are spending so much money to fly everyone home, which to me sounds reasonable and respectful. Yet how can I justify inviting 6 of my second cousins who are under 21, when none of my fiance's nieces and nephews will be invited due to the age limit? What would be the proper etiquette for a situation like this?