If you are over 16 it is illegal to have sex with anyone under 16 (or 17 in Northern Ireland). If you are under 16 and you have a sexual relationship with someone else, technically you are breaking the law.

Remember that it is not a defence that you didn't know he was under-age or he lied to you about his age. Under age sex can be a very serious crime.

If you are travelling overseas the same rules apply. Just because you are not in the UK doesn't mean you are beyond the reach of UK law and you could be liable to prosecution in the UK for child sex offences committed overseas.