[Kamikaze Chinchilla]

I think a reaction like this is normal, under those conditions. If he's playing the mmo with someone who's probably going to look for some form of sympathy or attention (considering he's the 'good person' and will try to comfort her...makes him feel like he's more needed/wanted), as well as the fact that she shares the same interest in the mmo as him..then most likely he'll start to gain a stronger bond with her.

I would be careful if I were you. Your relationship with him can become very frail very quickly. Watch out for signs that his interest in you is decreasing and prepare yourself just in case.