If a couple are living together in his house, which is mortgaged in his name only. He won't make a will, so if anything happens to him everything goes to his son, and presumably if anything happens to his son, to his son's mother.
A bad situation you may think, however, the couple have a joint life insurance policy, which is not linked to the mortgage and was taken out a couple of years after the mortgage. They are the beneficiaries.
If anything happens to him, then his partner will be paid out by the life insurance policy. Would there be any legal obligation on her to use it to pay off the mortgage? Or would she be able to walk away, leaving his son and his family to deal with the rest of the estate?