I think there are lots of situations in life, or in a relationship when one event can be the trigger that gains meaning for you and pushes you to think about your relationship, or whatever, in new terms.
Back in 2003 or so Stephen and I shared a townhouse with my best friend. My best friend had this little cat, Jade. One day Jade got stick and curled up in a corner and refused to eat. We knew something was really wrong, because our cat, Sam, who never got along with her, started being nice, and grooming her. We took her to the vet and they told us she was anemic and before they could even figure out what was wrong, they had to give her a blood transfusion, which was going to cost $1,500. This was about what the three of us, combined, made in a month, and was therefor well out of our price range. We took her home and started gathering money to have her put down. My friend arranged an appointment, and on the day the three of us were all going to go together. She was going straight from work, so I drove home to pick up Stephen and Jade. When I walked in Stephen was asleep on the sofa with Jade perched on his chest. I got the carrier and woke him up, and he told me he needed to shower first. I was frustrated, because we didn't have a lot of time, and he knew when the appointment was, and then he explained. Apparently, she had started crying and holding her made her stop. She was super weak at this point, and while laying on him had peed on him. He didn't want to disturb her when she was finally napping peacefully so he just lay there, soaked in cooling cat pee, and waited for me to get home to comfort her.
That is when I knew I wanted to marry him. Even though we didn't talk about marriage for another 2 or 3 years, I knew that day.
It can be difficult to express how you feel about someone until something happens which you can use as a metaphor to process with. If Redball's wife felt there was no room for her in his life, she had felt like that or sometime, but this even may have provided the concrete example she needed to process or articulate those feelings. That said, if she decided that night the relationship was over, instead of sharing how his refusal made her feel, the relationship was doomed for sure. Once one person decides a relationship is doomed, it always is.
The space in which a relationship exists is almost a shared delusion. The boundaries are created as the understanding of the two (or more) parties push against each other and create some thing that the relationship is. Like two people able to stand straight up from the ground by leaning against each other's back. If one stops trying, there is no way for the other to keep them both up.