"I Love Lucy" star William Frawley once called his TV wife Vivian Vance a "miserable c---t."

The claim was made by the late actor’s "My Three Sons" co-star Tim Considine. According to the 81-year-old, the vulgar insult was made when a lieutenant general and his adjutant visited the set of their ‘60s sitcom while he was in the Air Force Reserve.

On Wednesday, the actor told Page Six that at first, the quartet shared a pleasant lunch. But that quickly changed.

"I was thinking, ‘Hey, this is a great success. [Frawley] hasn’t said anything to put anyone off,'" Considine told the outlet. "I was pretty pleased with myself."

BETTY WHITE'S 'GOLDEN GIRLS' CASTMATE ONCE CALLED HER THE C-WORD

William Frawley Vivian Vance

Vivian Vance as Ethel Mertz and William Frawley as Fred Mertz in ‘I Love Lucy’, circa 1954. (Photo by CBS via Getty Images)

However, Considine claimed that the lieutenant general finally asked Frawley was it was like working with Vance on "I Love Lucy," which aired from 1951 until 1957. Considine said that’s when his stomach dropped.

"I saw it coming," he recalled.

Considine told the outlet that Frawley allegedly replied, "That miserable c—t."

While it was no secret that Frawley and Vance disliked each other, Considine described the actor as "a terrific guy." However, Considine noted that his job was allegedly to bring Frawley back to the set from Nickodell, a popular hangout for actors and crew members, where he enjoyed drinking.

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

William Frawley I Love Lucy

It was no secret that Vivian Vance and William Frawley disliked each other. (Photo by CBS via Getty Images)

"Sometimes he’d fall asleep in the middle of a scene," Considine recalled, adding that the writers made sure Frawley’s character "Bub" O’Casey was standing and doing something, such as sweeping the floor.

"He’d blow a line and say, ‘Who writes this crap?’" said Considine.

"My Three Sons" aired from 1960 until 1972.

Frawley passed away in 1966 at age 79 after suffering a heart attack. Vance lost her battle with breast cancer in 1979 at age 70.

CLICK HERE TO GET THE FOX NEWS APP

My Three Sons

Some cast members from the TV series 'My Three Sons', circa 1963. Clockwise, from left: Stanley Livingston, Tim Considine, William Frawley (1887 - 1966), Don Grady (1944 - 2012) and Fred MacMurray (1908 - 1991).  (Photo by Silver Screen Collection/Getty Images)

Back in June, Frawley’s "My Three Sons" co-star Barry Livingston told Fox News Digital that he enjoyed working with the actor on set.

"He loved to make me and my brother laugh by saying outrageous, sometimes quite vulgar things," the former child star said at the time. "When you’re eight or nine years old, it just cracks you up."

"He wasn’t too far from the characters that he played," the 68-year-old shared. "He was a very well-known, established character actor even before ‘I Love Lucy.’ And in those days, when it came to doing a television series, there were only three networks. And when you tune in to a TV series, 25 million other people were watching. So his fame really exploded. But on set, he just loved to make my brother and I laugh."