I can't figure out what I'm doing wrong to make the no-leak Avent Sippies leak. We've been using Nuby soft spout cups, but DS has learned that if he turns it upside down and presses down, all the milk will come out of his cup and he can play in it. So we're on a quest for a new, hard spout sippy cup. I bought a pack of Avents, and while the spout doesn't leak, when DS tips up the cup to drink, it leaks out of the little vent hole (and often time goes up his nose). Is there a trick to installing the valve or something else? Or should I just move on to another brand?
Thanks.
Re: Avent Sippy Cups Leaking?