While I thought the same at the time, since then I've adopted a more nuanced view. My guess is that she was planning to divorce him for a while and just used an opportune moment to actually do it. Some rumors that can be explained away are not something that would end a healthy marriage.

I always thought it was more to do with the fact that their youngest son had just turned 18. So he was probably moving out of the house to college. There is a big culture here in the US to "stick it out for the kids until they move out" mentality. So I just thought that is what they were doing.

Thought it was because his office behavior was sus.