His wife is addicted to enabling her adult children and allowing them to continue to make poor decisions.

Being financially stable often comes down to avoiding the dumbest possible decisions with your money. It can be difficult to know what a dumb financial decision is because dumb financial decisions are so normalized. The population at large is addicted to buying cars they can’t afford, renting apartments that cost them more than half their paycheck, and putting everything on a credit card they aren’t planning to pay off anytime soon. Are you bad with your money if you do all three of those things? Is one of those sins enough to ruin you financially? It all depends on the person and how much debt they’re comfortable with accruing. 

The dumbest financial decision you can make is cosigning an apartment or a car for a financially irresponsible person. It doesn’t matter if they claim that they will keep up with their payments. If they stop paying for whatever reason, the cosigner will be responsible for the whole bill. Do you really want to pay off a car that isn’t yours? If you did, you’d give the person the cash to pay for it up front.