I think D and sidhewolf have made some good points. I got the feeling reading this that some tried to kind of gloss over some of D's comments - forgive me if I have misinterpreted what was said, but I'm glad that someone expanded on what D originally brought up. I know ALL relationships take care and attention by both parties.
One of my vanilla sisters and her husband had a problem a while back. She has medical issues that make the physical acts of even vanilla sex difficult (back and neck issues) and she found out he was cybering and getting kind of serious with a lady online. She was devastated, and he felt like shit when he realized how it had made her feel. In this case it wasn't even the physical act (the online lady in question lived in another country), but the emotional hurt it caused. So, yeah, cyber CAN feel like cheating. The sad thing is, I can see both sides of their issue too - he obviously had issues that she couldn't meet and they were drifting apart. The upside - they've come through it and have gotten closer for it, but it wasn't easy. Now if they only had insurance that would cover the chronic pain in her back. I know, it's only one example,but I figured it was worth mentioning.