I've raised 4 kids, and have changed a ton of diapers.
To be honest, I was always a bit afraid at first, as I was obviously well aware of my own personal fixation with them.
But I can honestly say, that changing my kids never once bought out my "dark side" as I was concerned that it would.
If anything, I definitely didn't enjoy it at all. It's one thing to imagine yourself in a fantasy situation where you and others are getting changed together and it's intimate, but it's a whole new kettle of fish when it comes down to taking care of your kids.
And that's a good thing. Feeling mild disgust rather than any sort of pleasure actually made me feel better as a person.