Maybe your abandoning spouse had a period of hesitation.
He or she tried to end the affair, and told you that they were willing to work on the marriage.
In their panic and desperation, they cannot see how their actions are pushing their partner even further away.
They see their world falling apart and they begin to panic. But invariably, they do all the wrong things to try and save the marriage.
However, you still may have to pay up once that debt goes into collections.