I totally agree with makoto. Think about if the tables were turned.. Would he leave you for having cyber sex, or even playing with a web cam?
I do believe that, is cheating!!!
At least the worst part is already over... You know about it...
If he is betraying you, is he worth it?
Everyone will give you advice about what they think you should do, or what they think is right, but I believe if you are in this forum, you want advice from people that don't know you, so they can't tell you what you want to hear.
I know it can be hard, but personally, I would leave. To me that’s not okay. You are a woman, and not a toy. You deserve so much more respect! He needs to realize that.. Just follow your heart..