It would be good for all if our cultural attitude toward sex here in the US was more practical and mature. However, as you note, age of consent is a very impor

It would be good for all if our cultural attitude toward sex here in the US was more practical and mature. However, as you note, age of consent is a very important factor. The two families could be enlightened, mature and responsible, but if either kid is below the age of consent, then both kids are at risk of being registered sex offenders, and the enabling parents may be in for legal trouble also. I would prefer to take the Netherland's approach, but the legal issue trumps everything, in my opinion, in these hyper-puritanical United States.