>>717753495
Combination of 3 things.
1) We self-insert as the kid, we, as adults, wish that was us.
2) Men are biologically and culturally driven to have sex, so when a male has sex with a woman, regardless of the context, we don't register it as a bad thing, even if we're aware it was inappropriate.
3) Men are instinctively driven to protect women, and especially children. This leads to the direct opposite of 2, we don't register it as a good thing at all, regardless of context.
This is my headcanon, anyway. I don't claim to be a psychologist.