Locking up someones character - I couldn't care less about
I have two daughters I take the sexual extortion of minors over the Internet very seriously as do the laws in most civilised countries. What they are doing is not "a bit of fun"
The "we were fooling around" defence has been tried by many sexual criminals
What they are doing is actually illegal and I would urge once again the op to record what they are doing and inform his or her parents followed by the police. Its up to them to decide if a crime has been committed but we as a community should not condone or minimize this type of behaviour.
To do so shows a lack of understanding for the broader consequences and impact of such behaviour. I have nothing further to add.