Respectfully, I don't agree with
@Mr_B when he says: "I don't care if she looked and acted 30, he should do porridge for 5 years and be on a sex offender list for the rest of his life". For me it's all about whether he knew she was underage or not. If he
knew it, then it doesn't matter how old she looked or acted; of course he should be done for it. But I was at my cousin's place not too long ago and his daughter was heading out for a night with her friends - she's only 16 but genuinely looked in her early 20s. And I'm guessing she looked pretty similar a few months ago when she was 15. If some 21 or 22 year old bloke in a club that night saw her, I couldn't blame him if he tried to chat her up in the hope it went further. She did not look like a teenager.
As I say; for me it comes down to whether someone knows (or even just suspects) that the person they're trying to get off with is underage. I'm a happily married middle-aged man these days; but back when I was 18-24 years old and went to clubs, I certainly wasn't interested in anyone who looked very young, but if they looked roughly the same age as me, I fully admit I didn't open the conversation by asking to see a birth certificate. And I very much doubt anyone else here did either.
Once again - because this is obviously a hot topic - if a guy knows or has reason to suspect that the girl is underage, I'm definitely not defending him. Throw the bloody book at him. And in this case, Johnson seems to have admitted that he knew. So I'm not talking about him in particular. But I do have sympathy for someone who makes a genuine mistake with a 15 year old who looks 20.
(and for the avoidance of doubt; I'm talking about blokes who are in the same general age-range... if you're a 40 year old bloke who shags a 15 year old, the fact that you honestly thought she was 16 still makes you a dirtbag).