Rich Milf Slumming
A mature woman lives on the streets, getting by through casual blowjobs, sex and other depravities for money and food and shelter. She goes from one twister experience to another, until the month is over. She then calls her limo to drive her home, where she cleans up and awaits the return of her wealthy husband, who is none the wiser.
I'm still spitballing it, and I'm aware of the disease factors and other realistic things that would come in play, but maybe for fantasy reasons those can be ignored?