""So yes, on this view if a 9-year-old plays sexually with a consenting 9-year-old, even if one of them later regrets it, parents won't try to punish the other one. But if an 18-year-old plays with a 9-year-old, the 18-year-old is in for some punishment."

I still don't see how different in age nullifies what same in age allows here.

And why wouldn't allowances for later regret not be pertinent when applied to the 9 year old.

Over in the real world the realization that you've been defrauded nullifies the contract alone; there is no get-out-of-jail-free card based on the accidental demographic features of the parties involved."

If a 9 year old boy plays with a gun and unsuspecting girl who thinks bangs are cool and exciting, and unintentionally shoots her wounded or dead, then the girl, her parents and judges excuse his action by ignorance, stupidity and lack of propensity to remember why he was forbidden to play with the gun - excuses that a 18 year old boy would not benefit from. If that 9 year old boy plays with his penis and a girl who thinks her privates feel good to touch, and ends up deflowering her, is he enjoying the same excuses that a 9 year old boy with gun would?