Your scenario

In a society that was willing to go to great lengths to insure freedom for all, I can imagine a scenario. A rare 8-year-old girl says she wants to receive oral sex from an adult man. Perhaps after extensive interviews with 3 different psychologists, the prior permission of both parents, social worker investigation to rule out quid pro quos, and a waiting period, a judge could give permission with some confidence that her freedom outweighs any residual risk of harm. Such extensive measures would be appropriate because the baseline probability of a child being inherently interested is so low. We can imagine it -- but the procedure would also sit almost entirely unused.

Sounds like a cumbersome but effective deterrent for that girl. And what an 'alternative' way of going to great lengths to ensure freedom for all, with at least three people having to give permission.

Your hypothetical arrangement is very far from my way of thinking, as my way of thinking doesn't make much use of extensive procedures carried out by state institutions.

If a sensible person knows the girl, then it could be that that person could easily give an accurate appraisal of whether she really means that. A quid pro quo might complicate the matter, and then the main problem is if someone is pressuring her.