A very good friend of mine is in a relationship that's looking pretty serious. They recently asked me for some advice on how to balance the life of gaming (which basically means the way they'd play all day and all night without a care in the world) they've become accustomed to with the life of a good significant other.
Lucky for them, they asked someone -- me -- who's been in so many relationships it's hard to remember the actual number of people who have called me their boyfriend. And I've loved video games (among other interests) that my significant other's didn't necessarily enjoy. So balancing your personal interests with your relationship interests is pretty important.
So, there are a couple things you can do that'll help if you find yourself in this kind of situation. [NOTE: It's always easier to date someone who also loves the thing you love as much as you do but sometimes it doesn't work out that way. The heart wants what the heart wants remember?]
Show Them Why You Love Games
Sharing your love for gaming with your significant other is probably what you want to do. But that's not always going to happen. It definitely relies on them and if they're actually interested. You don't want to be the boyfriend/girlfriend who makes their SO do something they don't want to do.
But if they're interested a little bit, then go for it. Play with them. There's a lot they probably don't understand. You've been playing games for a long time which means you have an understanding of the language of video games. They won't know certain things that seem common to you. So when you teach them, pretend you're showing a little kid how to play games for the first time. They'll probably appreciate your patience with them and be happy that you shared such a big part of your life with them.
But if there's no chance that they'll be into video games or take to this idea then...
Manage Your Time Wisely
I know you want to play video games. I know you want to share something you love so much with the person you're dating. But they're not interested in it and it sucks (this is probably the position you and my friend are stuck in so read carefully). Even though they say they want to learn things that you like because you like them you know they're grinding their teeth through it. You know, the same way you grind your teeth through eating at Chipotle because it's their favorite place to eat.
So what you're going to have to do is time your gaming with whatever hobbies your SO has. Let's say they like going to the gym. So when they're at the gym, get a couple of hours of Call of Duty in there. What I like to do, or what I used to do, is time my gaming with when my SO would go to work. We worked different schedules so when they were out of the house, I'd play games on my own. When they want to have a night out with their friends, I'd have an night in with my virtual ones.
talk to your significant other about the time you need with them versus the time you need without them.
Communication is more important than anything you could possibly be interested in.