Lester was not a pedophile
I know I might get some flack here because I've seen some posts of people angry at those who defend Lester. But look at it through his point of view. The first time he saw Angela, he saw someone that was sexually awakened. To Lester, he was an example of Cleopatra, or Madonna, someone that was sexual and used it to their advantage. Every girl around her was a dampened version of themselves, but not her. She had opened Pandora's box. She was a woman. But the problem is (which he found out at the end of the movie) that she's actually just a girl. And yet, she was acting just like how an experienced woman should.
It was when she confessed that she was a virgin that her whole facade faded away, she wasn't this sexually confident woman, she was just a girl. And when Lester noticed this, he backed away and immediately started treating her like the father figure she probably didn't have.
That's why those kids pageants are so controversial, because parents put makeup on their daughters and make them look much older and sexual than they actually are. It's only when you wipe away the makeup, the attitude, and the facade that you realize they're just a small, vulnerable girl. The ones who are still attracted are the pedophiles.