@Charming Devil,
More you stress yourself over "inappropriate fantasies" the more those thoughts will pop into your mind.
Imagine if thinking of an elephant was the worst thing ever. Everyone who just read that would be horrible people. But you can't not think of something without thinking of it. Just one of those weird things abot how our minds work. But as long as things stay thoughts there's no problem.
But every time som knuckhead clergyperson rails against porn, masturbation, and evil thoughts, everyone listening is thinking of porn, masturbation, and evil thoughts.