Well it wouldn't happen here. According to s.13 of the Sexual Offences Act 2003:

(1) A person under 18 commits an offence if he does anything which would be an offence under any of sections 9 to 12 if he were aged 18.

(2) A person guilty of an offence under this section is liable—

(a) on summary conviction, to imprisonment for a term not exceeding 6 months or a fine not exceeding the statutory maximum or both;

(b) on conviction on indictment, to imprisonment for a term not exceeding 5 years.
Cutting the jargon, if you are under 18, and you commit a consensual sexual offence with a minor, you get a much reduced sentence. It looks as if there are a few bells and whistles to it, but that's basically it. He would still have committed an offence in the UK, mind you, and IIRC he would still go on the sex offenders register. But he wouldn't get sentenced at the adult tariff.

High Court judge Justice Roderick Evans directed the jury to reach a not guilty verdict, on the basis that drunken consent is still consent
At the risk of going back OT, I couldn't understand why this direction, which is perfectly correct, got the judge branded as some sort of woman hating caveman. I really don't think ordinary people, as opposed to lesbian columnists in the Guardian, find this difficult to understand. Willingly doing something you wouldn't normally do because you were drunk is just bad luck. Being so drunk you have no idea what is going on, that's a different issue. Have sex with someone in that state and you are going to be charged and rightly so.