When my middle one was two--very tall--one of the CMs at Chef Mickey's asked him how old he was. I think it was our waitress, but don't recall for sure. He told her he was 6. I cracked up as that was his usual answer and was totally unbelieveable. His 6 year old sister then chimed in, "You're three, I'm six!" Needless to say, we weren't charged for him. Every other meal we went to, they asked the ages of our kids when we checked in and that was it.
In fact, we just got back from a trip with 8 kids, 4 of whom were under three and none of us were ever asked anything beyond how old all the kids were at check in for the PS.