Could everyone please stop immediately freaking out over stuff like this?
Yes, the way it was presented was kind of shocking, but the actual backstory was intentionally left open. The husband thing could have been a joke for all we know. Or it could be one of the rather common scenarios where people only realize they're not straight after having married, de facto ending the romantic involvement with their spouse (and eventually find someone new) without getting a divorce for various reasons. Yes, could also be that they cheated, but we are not told. And, mind you, I think that was the entire point of the story: To make you think of these things. They definitely happen, heck, it could even be a criticism of the shitty discrimination that results in people finding it so hard to come out and not "accidentally" marry in the first place.
I understand the wish for happy yuri, I love that, too. But I think you can't have yuri without also now and then writing critical stories (critical about all the shit lesbians and the LGBT community in general) get. Please don't always assume the worst when something is not diabetic-level WAFF. :)