Taking a hooker to Disneyland... Help me get this joke

[Moneyline]

I live in Vegas and it seems like every hack comic in town tells a version of this one joke. It goes: "Why do people take their kids to Vegas? That's like taking a hooker to Disenyland." The joke always kills, but I don't get it.

One theory I have is that people find it funny because Vegas and Disneyland are supposed to be opposites, with the former catering to adults and the latter to kids. But hookers aren't the opposite of kids, so this doesn't seem to hold up.

My second theory was that people at shows & comedy clubs are usually drunk and will laugh at anything, but this doesn't hold up either because I've seen plenty of other jokes fall completely flat.

My final theory is that people just find the word "hooker" titillating, so they laugh when they hear it unexpectedly. This theory seems more plausable than the others, but it still seems like I'm reaching.

Can someone with a more advanced sense of humor than mine please enlighten me? I don't find this joke funny at all, but since I'm going to hear it every time I go to a comedy show I'd at least like to know why most people think it's hilarious.

Thanks.