We're going to a wedding this summer. It's a very smart, all day event with a black tie evening reception. But there's lots of kids attending, a picnic lunch with lawn games and the bride and groom are putting on a bouncy castle and other activities for the kids (the venue also has a play area). What would you dress a 4 year old boy in so he's smart but comfortable and can run around and make the most of the day? I'd prefer not a suit.