Guess I better make my kid a therapy appointment. I hauled her butt out of MK due to her behavior.
She still remembers the day, and has not repeated the behavior.
Good for you! I don't know if I could have done it at WDW, but I've frequently done it at parks, stores, the zoo, etc. "If you can't behave properly, we'll have to leave." And if the misbehavior continues, we go.
OTOH, I've seen a family member threaten her children with stuff like skipping their own birthday parties, not going to Granny's house for Christmas, etc. She obviously doesn't intend to follow through on any of those threats (nor any of the milder ones she frequently makes, for that matter), and her kids know it. Mom threatens and cajoles her kids to try to influence their behavior, but she never follows through or actually disciplines them. I love those kids, but I dread going places with the family because there's always drama between the kids and parents and I don't like my children witnessing that kind of behavior from people they love.
DH and I talked about it and decided ahead of time that we weren't going to make empty threats about leaving WDW if and when our kids misbehaved. We predicted a meltdown from our younger, higher-strung DD, but didn't have a single instance with her on our trip. My older DD had two "tantrums" at WDW; very much out of character for her. It wasn't the kind of thing that others probably noticed or that ruined our vacation, but it also wasn't something I was willing to ignore because we were at WDW or because she's normally very well behaved.
Yes, she was overstimulated; no, that didn't excuse her behavior. If we weren't on a very expensive, first-in-their lifetime vacation, and if it didn't affect the other three members of our family, we would have walked out the gate immediately.
Instead, she missed out on an attraction or two. We sat down on a bench and I gave her time to calm herself down while her dad and sister went on the ride. When she had another fit a couple of days later, she missed about an hour of rides and attractions while she and her dad sat on a bench and she got the time she needed to adjust her attitude. And that was the end of that.
I imagine that lots of stressed, hot, tired parents at WDW threaten to leave the parks when their kids misbehave, but they have absolutely no intention of following through. Kids are pretty smart and probably know this. If you don't mean it, don't say it.