if someone rubs it in, they keep talking about something that makes you feel embarrassed or upset. I know I made a mistake, but you don't have to rub it in.
Whenever he won money from a bet with others, he would always rub their noses in it by saying, "Thanks for the donation, suckers." (this being an example of how to rub someone's nose in it)
Someone who is addicted to obtaining money and building wealth. A money addict and fanatic. Breadheads often work more than one full-time job, and some even participate in illicit activities to "obtain the bread".