Unfortunately, a lot of computer and console games are designed for one person, and are not meant to played for a short time.
Maybe you could suggest investing in a Nintendo Wii, or two player games for the 360, so you could join in, and try and strike a balance - you do what he likes, and he could try and do what you like.
To look at the bigger picture, for any relationship to succeed you need to deal with problems while they are relatively small, or they will grow to the point where there is no going back.