This is a cute and short story.
You'd think you understand where the story is headed given the premise, but I enjoyed how the author subverted my expectations. Well, I say I enjoyed it but it was more like shock and sadness. The conclusion raises some questions for me, but I don't think they're ever directly confirmed.
I did enjoy the contrast in personalities between the MC and FMC. Perhaps I'm dense, but I still don't understand why FMC puts so much effort into her relationship with the miserable bastard that is the MC. Still, I don't necessarily dislike miserable, self-loathing MC's. Logically it also doesn't track why FMC doesn't tell her friend about her condition, but I guess the allure of the story is that MC and her have a special relationship.