I've done something similar to a kid that wouldn't stop running his mouth in the Vault. He thought that no one knew how to do it, despite everyone involved being veterans, and he spent the whole time whining whenever HE would die from a random Goblin or something. Kicked him before we finished. Had less to do with his age and more to do with being an idiot. At the same time, though, Kids are a real pain to play with more often than adults. When you get a whole lobby full of kids screaming, it's nauseating.