I actually surprised myself by not liking this one for one small but persistent reason. The divorce seemed tacked on, almost a Standard Literary Divorce, rather than actually fitting the characters, the story, or the setting. She "gave Mark everything," felt "empty," and blamed him, but despite her realization the marriage still ended. For that matter, although the character described the divorce as her fault, she didn't actually say any of this to her soon-to-be-ex, because redeeming the marriage through actual conversation isn't allowed in SLDs.
Of course, Mark was a jerk, too. The husband usually is in SLDs. He stormed into the house, made annoyed, gratuitous, and unforeshadowed xenophobic statements about the alien, and demanded a divorce. Since when was this an angry divorce? Since when was the narrator's ex an asshole? Why wasn't this mentioned before Mark showed up or referred to after? It felt like the divorce had to happen, so the author plugged in one of the standard divorces of fiction and moved on.
However, the craft of the piece was excellent. The author choose words well and the pacing was perfect. The alien was just alien enough for this kind of story - not too alien for empathy to occur, not too human for misunderstandings to occur, and with enough alien physicality to evoke his difference. The fact that one of the central narrative pieces - the divorce - felt bland and out of place spoiled the story for me, though.