He pleaded guilty to the charges. That’s all I know. All I’m saying is that there might be some damaging facts of the case here that he knows about — and you and I don’t — that motivated him to do that.
He was charged with having sex with a minor. He had no possibility of a case if he denied having sex so he admitted to it. The problem after that was the girl was a minor, something he may not have known but it doesn’t even matter if he knew or not or if the girl had ID to indicate she was 18.
The difference in punishment for soliciting a prostitute and sex with a minor is pretty significant.