I doubt Cathy would stop if Abby were to stop first, but the point is moot because neither one of them is willing to stop before the other does. You may consider one of them more virtuous, but the truth is they’re equally stubborn.
I haven’t actually seen the movie “Click,” except for a few scenes. I think I was annoyed with it because I had written a story on the same premise when I was about eight. (But then a couple years after that, a Goosebumps book stole my idea, so by the time “Click” came out, that story premise was much too recycled to appeal to me anyway.)