Interesting. I don't know if I'm the best person to answer this or not as I am 100% against cheating on your spouse for any reason so in my mind I am already pre-judging the man. However, I am a white guy who lived in Asia (Korea, Japan, and Hong Kong) until I was 20, so I know a bit about cultural differences. While it can be socially acceptable in parts of Asia for a married man to have a girlfriend on the side, it is pretty much never socially acceptable for an American man to have one. I can name half a dozen men my family knew as I grew up that openly had girlfriends outside their marriage, but I cannot think of one single man I know here in the US that has one.
I do not know this man and the sort of relationship he has with his wife, but my honest guess is that he is just biding his time, willing to take whatever you give him and secretly hoping you eventually decide to go further. Even if he is honestly backing off, the mere fact that he is putting himself in position to be tempted when he is married and has a kid, well, by American standards, that's pretty low. Here is probably what you can expect:
- It is highly unlikely he will leave his wife and his child for you, so you would never be more than someone he comes and sees now and then for a few days of intimacy.
- His wife would be crushed if she knew he was having an affair and odds are it would end in a not too happy divorce that would have a huge (and negative) impact on his kid. Now, his wife may never find out, but is harming her and their child a risk you can live with?
- Whatever intimacy you do end up sharing with him will only last so long as his job gives him the opportunity to travel to China.
- It's a dead end relationship that you might end up spending years of your life on him when you could be searching for something far more honest and fulfilling.
Could I be wrong? Sure, but the odds are not in your favor. You are not married, so it's bit easier of a choice for you as you won't be affecting any life but your own (assuming his wife never finds out that is...seriously, think long and hard about that.)
No matter what you decide, understand that the chances of this having a happy ending for you are not very good, no matter how honest and nice this man is to you.