The way the story is set up, getting together with Ayano would be the best thing for the MC. Ayano is even more forceful than her husband and will probably end up controlling the MC's life even more than it is now. However, the way her life is currently headed (moving in with a family she doesn't like for an indefinite period of time) sounds like hell.
She needs a course correction away from that, and unless she grows a backbone out of nowhere (she won't) she needs to use the affair as an escape route.
MC's fucked personality (always say yes!) is what started all of this, and it's just going to keep getting her into more trouble unless she can eventually control that impulse though. Gluing the wedding ring to her hand may be a good start (if she gets engaged to Ayano anyway).