@TimoculousPrime I hear good things about Fox and the Forest Duet. It's a trick taking game, and, while the original is competitive, the Duet version is cooperative.

Another one I've played is Time Stories. The original gives you a scenario and a timer in which to solve the mystery, so don't expect to win the first time you play. The newer Revolution series for Time Stories does away with the timer, in lieu of a points system. So, you're always going to solve it, but you're graded on how efficiently you did it.

There are also larger co-op games my SO and I have played a bunch, like Spirit Island and, most recently, ISS Vanguard and Monster Hunter World.