What is Mama's Dry?
1.
When the matriarch (or gay patriarch) of a party has run out of beverage and demands that a guest refill their drink. Usually accompanied with hand gestures either pointing at the offending empty glass or waving it around. Can also be posed as a question.
Luke: Alex! Mama's dry! Get me another vodka
or
Alex: I'm getting another. Is Mama dry?
See