Underlying vulnerabilities very likely made the new relationship possible.
However, there are long-term consequences that will come with that choice.
This time they wouldn’t abandon their marriage but would figure a way to work out their marriage problems.
They would not expect their children NOT to be negatively affected by the divorce.
Some are honest enough with themselves that they know step-by-step how everything came to be as it is now.
Others have more difficulty, their mind confused because what they are doing is so contrary to what they believe and value. Others blame it on their spouse’s actions or lack of actions.