Dating a married woman
The important thing about the married man is he’s probably coping with his limited marriage by doing something else (work, alcohol, substances, whatever consumes and distracts him).
The reality is he’s looking for love like the rest of us and afraid of what he’ll find.
The ‘other man’ is probably afraid that he won’t be able to ‘handle’ a love relationship with a fully available woman.
Triangles exist simply because a problem is not being resolved in a marriage.
Two people get married and have marital problems, instead of resolving those problems either by fixing the relationship or ending it, which by the way can be a valid resolution of a problem, a third party is brought into the relationship, and now you have a triangle.
Fundamentally, they are unstable, like three legs on a table.
Something always goes wrong, or at least it should, because triangles usually end up hurting people more than anything else.
In other instances his defenses are so thick he doesn’t read the signs at least consciously.
Personally, I think most if not all married people know on some level if a spouse is cheating, but that’s just my belief.
It’s hard to tell, some couples can pop out of a triangle and do the work of recommitment, others can’t and end up doing it apart, alone, or with someone else.