AceShowbiz -

Robert De Niro reportedly had a blowout fight with his wife Grace Hightower. According to an eyewitness, the star of "The Intern" and his wife of 20 years were recently bickering at a Manhattan bar.

Rumor has it, Robert and Grace are bickering over her coffee company, Grace Hightower & Coffees of Rwanda, as it's turning into a money pit. According to a source, Grace has frustrated business associates, as well as Robert, by dithering over simple decisions, and "changing her mind about how to run the business depending on who she spoke to last."

While fighting with his wife at the Manhattan bar, Robert allegedly told her, "I wouldn't have to keep making s****y movies if you didn't spend all my money!"

Grace's coffee company, which sources its fair trade beans in Rwanda, has parted ways with its biggest distributor, Whole Foods.

In recent years, some comedians including Joel McHale have teased Robert over his choice of roles, including those in "Dirty Grandpa", "Grudge Match" and "The Intern", which may not live up to his status as the multi-Oscar-winning actor from "Raging Bull", "Taxi Driver" and "The Godfather".

Meanwhile, Grace's defenders point to a slew of establishments which carry her coffee, including the Ace Hotel, the Breslin, Salvation Burger, Salvation Taco, White Gold, the Williamsburg Hotel and Robert's raft of hotels and restaurants, including the Greenwich Hotel and the Nobu chain.

A rep for Robert, however, denies the alleged fight, saying, "Your story is based on something that never happened from a source who has an ax to grind."