“Real Housewives of New York City” star Ramona Singer stopped by her neighborhood spot Pizza Beach on the Upper East Side Sunday afternoon — and left a lousy tip.

“She was rocking an all blue fitness outfit and wanted to grab a healthy bite to eat,” said a spy. “She ordered the Brussels sprout salad and a water. She was alone and rarely looked up from her phone during her one-hour lunch. She tipped $1 on her $20 bill.”

Singer didn’t get back to our request for comment.