I have burned a lot of brain cells trying to figure this out. Based on listening to lots of MAGA folks and reading too many comments from MAGA worshippers (almost all men, surprise!) I speculate that this attitude is prompted by several overlapping beliefs.
The most obvious reasons for Gaetz and his cronies to vote against sex trafficking legislation is that they know they themselves are vulnerable to prosecution under such laws. But why don’t his constituents see a problem? (Note that this is speculation.)
(1) Sex trafficking legislation is a trap crafted by Dems to discredit upstanding folk like Gaetz with false accusations. These bogus bills don’t address “the real problem,” whatever that is. (2) They profess moral outrage at trafficking, but their righteous outbursts come with obsessive description of the details of the crime. In short, they’re getting off on the stuff and pretending they’re not. (3) They figure some of the behavior the legislation limits is ordinary human (male) behavior. What’s the problem with hitting on teenage girls? It’s not only natural, it’s cool. Especially if you score. What’s the big deal about Trump lusting after his underage daughter? She was quite a looker, you know! (4) Finally, the old double standard: hands off my daughter, but yours is fair game.
Like Theodor604 says, it’s seriously creepy shit.