i have a daughter, she is 6 now.
So if your daughter comes up to you and asks you about this, would you lock her up?
Honestly I never slept with an underage girls, but I feel sorry for rejecting them. The parents were always on my side, as, like you say, I was not "trying anything". They actually excuse for the behaviour of their daughter and tried to get me to like their daughter. It was all just too much for me, but keep in mind, the world is not so simple.
So what would you do, if your daughter aged 15 runs crazy for a 30 year old and that guy is totaly passiv and extremly sympatic? And you witnessed that it was your daughter that picked him and made a move, while the man rejects.
Given that you dont think your daughter shouldnt have sex with 15 anyway. And why would you think a young boy who cant even handle a condom would be better for her?