Great friend of mine, sadly no longer with us, was married for 12 years and both ended up in affairs and eventually divorced. My friend re-married, his ex did not, but they both remained with new partners for 10 years or so and one day re-met by pure chance. A year later both were divorced and married to each other again!! And remained happily married until he died.
I make no comment other than that there are no “rules” where relationships are concerned and we can only judge from our own experience, which might be quite irrelevant for two other people.