Search Results: using a webcam

My boyfriend and I have been together for 4 year. Living together for almost three!
Very early on in our relationship he cheated on my when he was very drunk. It took a while but we worked through it. A month ago I looked at his snap chat top friends for fun and it was a random girl. When I asked him about it, he said it was a random girl who added him. As I had her snap chat name I sent her a message and she said they met through a video chat website called omegle. When I asked him about this he admitted he lied and he had met her on omegle. But he said he only went on there twice. I was told omegle can be really sexual but he assured me it wasn't. He was just looking for someone to talk to as he has a lot of time home alone.
Yesterday when I was using his computer to look something up, under recently visited it had a couple of webcam websites. I had a better look and there was 2 webcam sites and several p*rn websites (from what I could see, im not very good with computers). The p*rn doesn't bother me. However the webcam sites do. I see them as being more personal as you can chat to them. When I asked him about it he said he doent chat to them so its the same as p*rn.
However due to his past I don't feel like I should be letting him away with this. After I found out about the girl he had been chatting to I told him it was his last chance and if he did anything again it was over! And Im not sure if this is bad enough to end it, but I don't want to be a push over.
We have a really good relationship. We hardly fight and if we do its about doing dishes or something silly. We have a lot of fun and he is like my best friend. We have a really good sex life. We are also planning on going overseas for a couple years next year. He is younger then me and I have talked with him about how I worry he isn't ready for such a serious relationship but he assures me he is.
I don't know what to do.
Any advice and ideas are welcome!!!