We invited my 7 nieces/nephews were invited to our 100% OOT wedding, but no other kids. Reason? Because I have 24 first cousins with 95% being married and 98% having procrated 65-something kids between the ages of 4-33. That does not even included friends or DH's side of the family. Just mine. You have to make a cut somewhere and mine was at my nieces and nephews. Not one of of our guests who had young children declined our invitation - remember is was 100% OOT. One even had a 6 month old. It's standard in our social circle to invite siblings, first cousins, nieces/nephews, WP members and children of the couple regardless of age. None of us think twice about kids not being invited. Actually the assumption is they are NOT invited. Most parents start looking for the babysitter as soon as they hear the wedding date being announced.Don't take it so personal. Inviting your kid could set off a domino effect that would mean 30 other kids would have to be invited. At some point every couple has to make a cut. If it's between my good friend getting 2 seats or your 2 kids, I'm going to pick the person who not only am I closer to, but will actually remember the event.