Anti-Spill Sippy Cup? [updated]

I feel like I am constantly on the search for the perfect sippy cup.  We have tried maybe 8 so far, and of those I am happy with three.  The Nuby No-Spill Flip N’ Sip Cup is not one of them.  Maybe it was human error, but I put water in this cup for my son the first time we used it, shook it upside down, squeezed the straw, and was I happy to see that it did NOT spill. Off to a great start.

I gave it to my son, turned around to put something away, and when I turned back I found that he was splashing his hands on his high chair tray and that he had sufficiently soaked himself.

I am not 100% sure how he managed this, but I suspect it is all in the straw.  It seemed that if he squeezed the straw with the cup upside down the water poured out, which he apparently figured out very quickly!  I have not used the cup again since. I am willing to give it one more try to see if I just assembled it incorrectly.  But, before that happens all our other cups will need to be dirty! 🙂

UPDATE

Dad here.  So we’ve given this cup several more tries, and it is better, but not perfect.  We have some issues trying to reassemble it (getting the straw through the hole in the top can be frustrating,) but the leaks are minor.  Our son did like the flip top a lot.  So much that he would get distracted and play with it .  …Not sure if that is a pro or not. 🙂

We give the Nuby No-Spill Flip N’ Sip Cup 3 of 5 stars because it leaked heavily upon first use but seems to be improved after additional usage.