Am I betraying my boyfriend with virtual world?

I have a relationship my boyfriend but at the same time I have another boyfriend in virtual world(by chatting). I don’t tell him about my relationship in virtual world and he do the same thing. Somehow I don’t feel guilty for my action since he too has his own relationship with other people(including girls) in virtual world,and most of my friend say that everyone has his/her relationship in virtual world and in real world because it’s just a virtual world where everything unreal.
I also fake my identity while I’m engaging in virtual world and I know people in virtual world can be different from their reality,and people can fake their real identity.
Am I really betraying him?,is he betraying me?,and do you think lie is something acceptable in virtual world?