In this kind of triangle with two men and a woman, there are instances when the two men fight over the woman.
This kind of drama is amusing only because if they know how connected they both are and how much they have in common they might realize that it would be more profitable for both of them to have a conversation together about the whole thing in a coffee shop or something.
In some instances he ‘knows’ his wife is cheating on him and looks the other way.
In other instances his defenses are so thick he doesn’t read the signs at least consciously.
A lot of misery is avoided with a respectful ending and opportunity to start again with someone else after a period of sincere efforts to fix a love relationship.
The point is, a triangle happens when two married (or simply committed people) don’t fix their marriage.
By the way, when people say they are afraid of intimacy think ‘exposure’ to what they themselves have difficulty accepting in themselves.