I'm so impressed you lasted so long without taking him! We go often for the Thomas the train set that they have set up there that the kids can play with for free. Plus they have AC and we didn't have that for a long time...
Well, he is very difficult.
They had this really complex miniature train system set up and he made me hold him up for 10 minutes so he could inspect it. If I had put him on top of the glass case where he really wanted to be, he would have been on all fours inspecting it until midnight. He screamed for another 10 minutes because I wanted to go look at something else.
We have to carefully think through what we do with him because he will argue with us or come back with something original.
For instance, just today he was being a handful and DW told him.
"Mr W, if you keep doing that, we'll make a trip to the bathroom and you won't like that!"
"Oh, I'll like it Mommy! IIIII WILLLL LIIIIKKE ITTTT!!!"
On other occasions, lately, he will call our bluff. We'll threaten with holding something from him. He will go get it and hand it to us then keep doing what he was doing. Or, get it and wave it around, taunting us with, "Here it is. Come get it."