This is for the best, I think, they're both married, at most they only had a few encounters out of work, it will be better if they notice how wreck is their marriage and divorce from their partners because both of them are unhappy as things are right now.
Michi thinks everything will be fine as it used to be before, but that's because she doesn't know her husband already cheated her.
At least Niina already notice things won't fix with her wife no matter how hard she's trying to save her marriage.