It's safe to say that it's dangerous to sacrifice your personal relationships for a hobby. The key to avoiding such destructive behavior is communication and I instruct my clients who are dealing with addiction to engage in this kind of dialogue with their loved ones:
Detach from emotions. Try not to let responses be emotional, but rather focus on the facts and the truth.
Set boundaries. With a gamer, they may need to quit cold turkey, or just rebalance their lives. It is so important to make sure you're on the same page when it comes to expectations about what needs to be done about the hobby or addiction.
Have fun together. Make a list of the fun things you liked doing when you first met. Substitute positive addictions instead of negative. Of course, doing relatively easy things like exercising together, having sex more often and cuddling are good places to start. These things will cause the same adrenaline release people get from gaming.
Couples should utilize these skills whenever they feel like gaming is beginning to eclipse their relationships. It's important for you to not let the stress get the better of you and to keep engaging in honest conversation.
To read more about saving your relationship, check out Dr. Bonnie's book, "Make Up Don't Break Up." And see her talking about the mind/body connection here.