My boyfriend is an online gamer as well but he doesn't play as much as your bf. My bf however used to play games for a long period of time (still not as long as your bf) and whenever he plays his games it makes me feel as if I wasn't there . But I talked to him about it and he reorganized his priorities (such as his work, school, games....) now he doesn't play a lot but once in a while there would be a long game > then I would just not complain and allow him to play his games cause he is still a human being and the games relieve him of stressful things that are bothering him.

Anyways, I hope it goes well for you and your bf. It is important to understand why he plays games too =)