Wonder why you haven't seen veteran actors Slyvester Stallone and Richard Gere share the screen? There's a couple of reasons the Rocky star will absolutely never work with the Pretty Woman actor.

They co-starred for a hot minute, but their time onscreen was cut short after they had an on-set fight. But that wasn't the only thing that produced bad blood between the actors. More than a few rumors have fueled their feud, including one about a certain princess and...a gerbil. Yeah, Hollywood feuds are weird.

Either way, it seems a bit strange that Gere, the Buddhist, is a part of one of the most notorious Hollywood feuds.

It All Started With Some Greasy Chicken

In 1973, early in both actor's careers, Gere and Stallone were set to appear in the 1974 film The Lords of Flatbush. It was (would have been) Gere's first film. He was cast as the protagonist Chico Tyrell, while Stallone played Stanley Rosiello. But it wasn't meant to be.

Following their on-set fight, Gere was fired after only a couple of days on set (we're surprised there's even photographic proof of them on set.) Filmmakers found that it was easier to get rid of Gere following their fight over their lunch and Gere's ego. Stallone was by no means a veteran actor at that time, but he recognized Gere was impossible to work with. He explained the fight during an interview with Ain't It Cool.

Related: 10 Times Celebrities Made Up After Their Public Feuds

"He would strut around in his oversized motorcycle jacket like he was the baddest knight at the round table," the Rambo actor said. "One day, during an improv, he grabbed me (we were simulating a fight scene) and got a little carried away. I told him in a gentle fashion to lighten up, but he was completely in character and impossible to deal with. Then we were rehearsing at Coney Island, and it was lunchtime, so we decided to take a break, and the only place that was warm was in the backseat of a Toyota.

"I was eating a hotdog, and he climbs in with a half a chicken covered in mustard with grease nearly dripping out of the aluminum wrapper. I said, 'That thing is going to drip all over the place.' He said, 'Don't worry about it.' I said, 'If it gets on my pants, you're gonna know about it.' He proceeds to bite into the chicken, and a small, greasy river of mustard lands on my thigh. I elbowed him in the side of the head and basically pushed him out of the car. The director had to make a choice: one of us had to go, one of us had to stay.

"Richard was given his walking papers and to this day seriously dislikes me," Stallone concluded.

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It's not the fact that Gere got mustard on Stallone; it's the fact that Gere seemed to have no regard for anyone else but himself in those early days. That's what got him fired really and replaced with Perry King.

Some Think Stallone Started The 'Gerbil' Rumor

There are rumors that Stallone, possibly in the way of revenge for that mustard stain, started a rumor, a scandalous NSFW rumor, about Gere in the '80s. If you're not familiar with the classic Hollywood myth that involves Gere and a gerbil, here's the story.

In the early '90s, a myth started that Gere had been rushed to the hospital for an emergency "gerbilectomy," in which doctors had to remove a live gerbil from his rectum, which he inserted himself. The legend has become so well-known that it's appeared in Saturday Night Live and Wes Craven's Scream.

According to Screen Rant, Stallone denies starting the rumor, but Gere apparently thinks it was him. Meanwhile, Uproxx writes that Gere stopped reading the newspapers because of such rumors.

They Almost Came To Blows, Again, At An Elton John Party

Elton John, of all people, witnessed another alleged physical altercation between Gere and Stallone. In his memoir, Me, John revealed that the two actors once fought over Princess Diana at a dinner party he held for the former Walt Disney Studios chairman Jeffrey Katzenberg while the singer worked on The Lion King in 1994.

This was also around the time Princess Diana had split from Prince Charles, so Gere and Stallon apparently thought they had a shot at the newly single icon.

Related: Sylvester Stallone's Method Acting Landed Him In The Hospital

"Straight away, Richard Gere and Diana seemed very taken with each other," John wrote. "As the rest of us chatted, I couldn’t help notice a strange atmosphere in the room. Judging by the kind of looks he kept shooting them, Diana and Richard Gere’s newly blossoming friendship was not going down well with Sylvester Stallone at all. I think he may have turned up to the party with the express intention of picking Diana up, only to find his plans for the evening ruined."

During dinner, John recalled that the group noticed Gere and Stallone were absent. It was John's now-husband David Furnish who discovered them "squaring up to each other, apparently about to settle their differences over Diana by having a fist-fight." Furnish was able to break it up, but there was still tension.

"After dinner, Diana and Richard Gere resumed their position together in front of the fire, and Sylvester stormed off home," John wrote. Apparently, Stallone yelled that he "never would have come" if he knew "Prince f**king Charming was gonna be here." Meanwhile, Diana was "completely unruffled" by the ordeal. Since then, Stallone calls John's version of events a "complete fabrication."

We don't know what to believe about any of these stories, but it's always interesting trying to picture these kinds of Hollywood stories. What we'd give to a fly on the wall at John's dinner party and that Toyota in 1973.

Next: Who Is Sylvester Stallone's Ex Wife Sasha Czack, And What Does She Do?