Bless you happy gamer couples, gotta figure out where you get your women...
We're around out there. 
There's an assumption that having a couple who both play the same game is a good thing. What happens if one is way better than the other; there's always some kind of power struggle in a couple's relationship and this could all lead to arguments. On the rare occasions I have played with couples, it seems to degenerate into bickering because they expect the other to help them more e.g. "Honey, I was only 6 feet away from you, why didn't you revive me!" 
My husband and I always had a ball playing ME3MP back when he still played (he has since moved on to the gigantic black hole vortex that is GTA V 24/7). He only ever played a Krogan, though, so it was sort of funny. I was very protective of him, though. Others in the lobby would chuckle when he'd get himself too deep into a spawn with his meleeing and I'd come rushing in trashtalking the enemies to get their grubby paws off my mate. LOL
My grandest moment gaming with him was this one, where my Turian Sentinel made the Ultimate Sacrifice™ to ensure he got his commendation pack: http://social.biowar...ndex/15264825/1
I think he mostly moved on because I was starting to progress to higher levels of gameplay (Silver and Gold at that time) while he just wanted to stay in Bronze, but he didn't want to feel like I was bored playing that level with him, so he eventually drifted to other games. 
How the hell do you men find women who are interested in video games?
Every GF I have ever had (including my current one) see me playing video games and give me that roll of the eyes and the "Isn't it time for a grown man to stop playing kids games" attitude ... not that it's a huge deal; but in my experience there aren't that many women interested in playing vids.
The closest I ever got to this was an ex who liked playing Sims
I mostly end up playing w my dad and / or brother ...
While I run into a lot more women than expected when playing this game online, we seem to be spread pretty few and far between. I myself do not have ANY female friends in my real life who game. 
Not really sure what advice to give, but my husband found me at the local dirt track. Or, rather, I found him. Or we found each other. However you wanna put it. LOL But I was a worker there and he was a racecar driver, and we just so happened to both be gamers, too. 