I think MLC doesn't become MLC unless and until there is a Crisis, by definition. What does the crisis entail? - leaving a family - engaging in fantasies of independence - like becoming a teenager again - trying on a new identity - new clothes, hair, tattoos, piercings, cosmetic surgery, new boobs, new manner of speaking, new interests - shedding or shirking responsibilities - running up credit card debt - walking away from commitments - mortgages, jobs, spouses
Just my armchair analysis, but it feels like many of these things are sort of fuzzy, or we deal with them differently. Like the credit card debt thing - in many cases a spouse might look at that and say, "well, we've made a mistake here, let's figure out how to get back on track." In other words, it is viewed as a mistake but not a sign of MLC.
The "new identity" is viewed sympathetically, too. I mean, who wouldn't like a makeover once in a while? a new wardrobe can really refresh you.
But it's the affair that is taken as the irrefutable sign by the casual observer.