a 20 year old guy who "gets it on" with his 15 year old girlfriend should be tried and executed for raping a child.
I'm not sure about that one. The current state of endemic sexual immorality is so far gone that a whole lotta people would be dead.
But I do posit that mature men who have sex with underage girls should be publicly beaten. Public pain and public shame are the only punishments that will work. Societal disapproval is necessary, and the girl shouldn't get off scot free either.
When kids grow up in fatherless homes, or other kinds of broken homes, they often have no moral compass and no foundation in their lives. Children need a father and mother who set boundaries and rules and are good examples. It pains my heart to see how so many children are raised now, and what becomes of them.
Another side point is that in previous generations early marriages were common, and were generally as successful as any other marriages. Now kids are made to feel that if they marry at all it should be in their late 20s, and they should have a series of sex partners beforehand.