Thanks!
He definately likes to flip the cup and play with the liquid. He actually does this with all of his cups, straw sippys and regular sippys. He sometimes does this near the end of the meal, so I take it as meaning that he is done drinking and now just getting bored/tired of drinking. by then the meal is over and we move on. I try not to really react, I just move on. I guess he can't spill as much or as quickly, so its not a big deal.
the problem is with the open cups, he can dump it so quicky, rather then it just dribbling out....so if he does this at the begining of the meal, its very frustrating.
maybe he'll just get used to it and the novely will wear off. he definately gets lots of play water time, but seems a bit obsessed with any water/liquid at the moment.
I think I'll just slowly add to his open cup, he can have a couple oz at a time and se how he does.