Been with my boyfriend for 2 years. We don't live together or have any dc together.
About a year ago I found out he was sending and receiving dirty messages from a woman on FB and was still actively registered in POF.
We sorted things out, he closed POF account.
About a month ago I got suspicious as contact with him got less and less so I checked his emails.
He is on lots of dating sites
. Most he can't even read the messages as not full member. One site I managed to get on his profile and have been reading his messages.
He has messaged quite a few people saying he'd like to get to know them. A few have replied, he gave one his Mobile number.

None of the messages I've seen are of a sexual nature just getting to know them type chatting.
But to me this is cheating and I don't want to be with him anymore. I've hardly heard from him in the last 2 weeks anyway.
So what's the best way to end it? To me, he doesn't deserve more than a text! As it's the holidays I don't really get time where I could phone him and I'm not sure I want to talk to him right now.
Also how do I tell my DC? They are 16, 13, 10 and 9. They know him quite well as he has been round here quite often and his 6 yr old DS who lives with him.