Need help please about DS/skype/internet

[catkin14]

I have also put this in parenting but need some quick thoughts!
I need some advice for this one please, this is new ground for me.

I have a 14yr old DS, he will be 15 in november. He is tall and goodlooking, outgoing etc.
My Exh and I split in march after a long marriage, and although my DS on the whole seems ok (despite Exh being a total idiot).
LAst week he got talking to a girl on skype via Minecraft. Originally she said she was 19, but then changed to 16. She is in USA.
Over a few days he became a very different DS, on his ipod all the time messaging, very secretive and snappy.
I was worried so, and this is shameful but I felt I had to given his age, looked at his skype messages between this girl and him.
I was shocked to say the least, she asked him if he was circumcised and that if he wasnt she wouldnt 'put it in her mouth or her hand but would still fuck him'.
I talked to him about this, without saying I had read his skype messages because i was very concerned that this was someone actually a lot older than she said.
I felt the chat we had went well and that he understood the dangers of talking to people you really dont know.
He is now talking to this girl on skype again, I wouldnt have a problem with this if I hadnt read some of the things she had said.
I have asked him if his girlfriend knows about this other girl and he says she does.
I am alone due to marriage break up, although EXH would have been totally useless) and I dont know what to do.
I dont want to have to ban him from skype, but I think he is very flattered by the attention, she is a very attractive girl by the look of her picture.
What do i do?? I also know that saying no to a teenager is like red rag to a bull..!
Help!

[cozietoesie]

Just go to CEOP, OP.

[Winterwood]

Even if she is female, anyone could be at the computer with her. At any rate, even if she is an older teenager - and if she is she is hardly a positive influence as her behaviour is atypical of most well balanced teenagers - it isn't a very useful habit for a 14 year old boy to be forming.

I know his
Dad isn't helpful but is there another person who might discuss online behaviour with him?