pet millionaire

A millionaire who is happy to provide their time, money and/or other assets they own to their non-millionaire companion without expecting them to repay that with any kind of service or favor in exchange for their commitment, their priority being their companion's wellbeing. (Note: explicitly not a sugarbaby-sugardaddy/sugarmommy type of relationship, and you ougth to treat your pet millionaire with respect, too.)

Pet millionaires are mythical creatures.
My millionaire is not a pet, they're family.