Madonna took her own wine when she went out to dinner on Saturday night.
The 53-year-old singer and her boyfriend Brahim Zaibat dined out at the Osteria Cotta on New York's Upper West Side, and surprised fellow guests when she whipped out her own bottle of alcohol and two crystal glasses.
An onlooker told the New York Post newspaper: "She brought her own red wine in a bag, along with two beautiful crystal glasses.
"They poured the wine and immediately put the bottle back in the bag, so nobody could see what it was. At the end, they took the empty wine bottle and the glasses with them. We couldn't figure out if Madonna prefers specific wine or is a total germaphobe."
The couple ordered an arugula salad, pizza margherita, bruschetta and a side of roasted cauliflower.
When they finished, the 25-year-old dancer picked up the bill and paid by credit card, and the 'Celebration' hitmaker ordered him to tip well.
Madonna recently claimed she will only date men who her children – Lourdes, 15, Rocco, 11, David, six, and Mercy, five – will respect.
She said: "It's important that my children admire and respect this partner that I would choose for myself. Especially for my sons, who have their father but they need a male role model as well.
"So I need to keep this in mind: What is this person modelling to my sons, what kind of man is he, what values does he have, what energy is he giving off? Because they are impressionable. It's so important."