Why are you two arguing about how being a gold digger works? You're both right: they sell sold out for some old dude with money; she probably also pretends to be exclusive with him, and probably isn't. She is showing she will do anything for money. When a relationship is based on money, pretty much means don't expect any real loyalty. So she may or may not be cheating on him now, but wouldn't surprise anyone (including him) if she does