Dude is funny, but that's a sad situation.
This is one of those examples of a guy not leading, and the woman not taking the form of the bowl or whatever the metaphor is.
That is, if the guy led, and let's say he was into Renaissance fairs, she'd probably go along with him and dress up because she loves that about him.
Instead, he's doing the following, and it's clearly sapped his energy.
Option one would be to dump her but without being mean about her Disney interest. Just say it's not working out and end it.
Option two is to tell her you don't like it much but will continue, and that once a year they're now going to go to a new MLB park or whatever he likes.
Option three, if she's otherwise nice and hot, is to make the most of it. Tell her you want her to buy a new Disney nymph/princess outfit every year and fukk her brains out at the hotel. Little Mermaid, Tinkerbell, Snow White, whatever. Maybe even get a threesome with one of those co-ed employees and an extra costume. What, I'm the weird one?
****EDIT**** upon further consideration, I'd lay dollars to donuts Option 3 is what she wants.