Aha. I'm on Second Life. I make a lot of money on there running a fake slore house. You wouldn't believe how many men come on there that are married to have "fake sex" with women. Some men I've had to ban because they ask for certain scenarios that are inappropriate like eating feces, or pedophilia. Yah. So In reference to the post, I think it's cheating-- it's emotional cheating. It's one thing if he just kept it online, but asking to meet in real life? Absolutely not.
This actually reminds me of when me and my aunt played World of Warcraft and she got caught up in our guild with the headmaster. She LEFT her HUSBAND and 4 KIDS (took the cat and dog though) in the MIDDLE OF THE NIGHT and moved to Colorado and got remarried to the Headmaster of our then guild. Not telling you what to do, but I would leave him with the QUICKNESS. It's too common unfortunately...