Based on our experience, I would be a little more worried about the adults losing theirs. They will pop off if they catch on something. Be sure to keep an eye on it when you are picking up, or putting down things. Mine popped off once or twice when I caught it on my purse as I was picking it up or putting it down. I've seen others have the same issue when taking off or putting on a backpack- I've picked someone's MB up off the ground and handed to them when it popped of as they were messing with their backpack. Also be careful if you are lifting or putting down a child and be sure you have it on after doing that, we noticed that is when they tend to pop off quite a bit. Also when swimming, they can catch on the side of the pool if you were holding on to the side and swim away and pop off. We have found one in the pool and turned it in before. We have had a couple of magic band trips and DD never really had an issue with hers, it was DH and I that had both of ours pop off once or twice while doing things. They do stay on pretty well, but you just need to keep an eye on them when you are picking up and putting down things, and be sure you have them before leaving a pool area. Now, a 3 year old might be another story. My friend's DS did not like wearing it, so he yanked it off and threw it in the bushes the first day. (Since Disney bushes can have snakes, you don't want to go digging around in them!)