When I was in my early 20s, after my mother went off the deep end and my dad was living in the hospital across the state, my mother decided she was going to ruin my dad's life. This might sound hyperbolic, and I don't know what she was actually trying to do or even if she knew, but I think "ruining my dad's life" sums it up rather well.
As part of the deal for refinancing the house, she got a check for $40,000. It was all gone within three weeks. No one knows where it went. She had elaborate plans, such as renting a bus and taking troubled orphans to the movies for a day, but none of it ever happened. She had previously vowed to fix up her house, buy her parents a house, and pay for my wedding, but unsurprisingly none of that happened either. The money just disappeared, as money in her possession so often did.
Not long after, my mother called me and told me she wasn't paying the mortgage anymore because she wanted the house to go into foreclosure so that my dad wouldn't have a home anymore when he got out of the hospital. Please understand that I am not claiming to read her mind -- wanting him to be homeless was the explanation she gave me. It was her house too, and it was where she lived at the time, so I don't know where she planned to go. I somehow doubt she had a plan. I decided to intervene because one or both of my parents becoming homeless could adversely affect me personally even more than intervening in their broken marriage would, and I went about setting up a joint checking account with my dad at a bank in my town, far away from my parents.
It isn't easy to set up a joint account with someone who is bedridden in a hospital halfway across the country, but with the help of a polite customer service agent at my bank and three-way calling, we did it on my lunch hour. Then my dad had to put through paperwork to have his veterans benefit checks direct deposited to our new joint account rather than his account with my mother. This was the start of my managing my parents' finances. This was how I found out just how much money they had.
When the first check went into my joint account with my dad, I contacted the mortgage company. It's generally really hard to get people to talk to you about someone else's account, but if they're some kind of debt collectors and you want to give them money, they really don't care who you are. My mother hadn't paid the mortgage since before the refinance, so they owed more than one payment. I paid it up to date. I changed the mailing address on the mortgage statements so that they would come to my apartment, after making sure there was no way I was somehow taking on my parents' debt by doing so. Then I transferred the remaining money into my parents' joint account for my mother to spend as she saw fit. This is what I would do on the first of each month.
Soon my mother called my dad in the hospital and told him that, if he didn't give her more money, she was going to sell all of his possessions. The problem with that was that all of the money that wasn't going toward the mortgage was already going to her every month. Unless you count his comparatively meager social security checks that my dad set aside to pay the property tax on the house, there was no more.
My dad had tens of thousands of dollars worth of musical instruments and amps and related equipment. My mother sold all of it. She also gave someone his computer in exchange for a second used refrigerator she decided to keep in the garage. All the while, she called me regularly to complain about her week and make money- and divorce-related threats. Once she said I had to send her $2k of my own money or else she would spend the money my dad had set aside to pay the property taxes on the house (I sent her nothing). Another time she threatened to file for divorce unless my dad sent her an extra $2k. I don't know why the number was so often $2k, but it was.
That's around the time I convinced my dad to file for divorce.