I work in the mortgage industry and have been doing it for a very long time. My best Sales Fails story happened about ten years ago when I was an LO (Loan Originator) for a big lender. I got a web lead for a married couple looking to do a home purchase and I prequalified them and they started shopping around together for a house.
They found a house they liked and got an accepted offer. We did all the paperwork, they did their inspections and everything else, and we were all set to close at the end of the month. It was a done deal and had gone really smoothly, with no income or home issues. I was already counting the commission from the deal.
Well, about a week before the closing, I called the couple to confirm a few last minute things, and neither one of them would return my calls. This was not a good sign. Finally, a few days later, the wife called me and was extremely apologetic. She told me that her husband had decided to leave her for a "young girl" that had been hired at his company, and that they were no longer buying the house together. I didn't even know what to say. She sounded more angry than upset and was venting to me about how absolutely disgusting he was.
Needless to say, the deal did not close. They backed out of the deal and lost like $10k in earnest money. I never heard from the husband, so I'm assuming the wife told him she would handle it. I always wonder what happened to them. Maybe I will look them up on social media.