Whooo - I didn't even remember posting this!
The guy that asked to bring his kids ended up not bringing them, but they only stayed about an hour (and only a few others had shown up by the time they left, so they missed the party!)
BUT a guy that DH works with brought his 15 month old.. granted they were all in costume, but we did have to worry about a toddler underfoot and I was freaked since we'd told Guy A that there were no kids...
so I was embarrassed and DH did pull aside Guy A and told him that we had no idea that the toddler was coming, so we didn't look like we excluded his kids on purpose.
I totally love kids (would love to have a few) but a party with drinking and scary stuff is no place for little ones.