Pedophiles, ephebophiles, and pederasts do have an idea. They've been practicing it for 2600 years, since the days when Athenian fathers had to provide their sons a pedagogue when they went to gymnasium. Pederasts were always hanging around the ball court, trying to initiate conversations with the boys.
Getting boys to "come across" is an ancient, ancient art with pederasts. That you should express skepticism in the face of such a lengthy accumulation of human experience with deviancy is frankly surprising.
Of course, I have no idea why some women allow their husbands to molest their daughters either.
"Allow" assumes the mothers know what's going on. Usually, they don't.
Sounds as if you've put a lot of research & study into it.
However, it does surprise me that something that has no evolutionary basis, has been proscribed by most if not all religions & cultures, and frankly seems as if it would be more uncomfortable than pleasurable has survived for this long, and has people who "choose" to practice it.
Why would anyone "choose" that?