Claire Danes and Leonardo DiCaprio were not star-crossed lovers. They weren't even star-crossed co-stars.

In fact, their relationship couldn't be any more different than their character's from Romeo + Juliet. When you have a more complicated relationship than the Shakespearian lover's, you know it's bad.

DiCaprio might have a really great working relationship and friendship with his two-time co-star Kate Winslet and most of his other female co-stars, who think he's an absolute gentleman, but his relationship with Danes was a complicated one.

Danes didn't have conflicting feels about her Romeo because he was a diva or anything. She had a love-hate relationship with him, so she certainly didn't want to work with him a second time in two years by auditioning for Winslet's Rose in Titanic. He's a bit overrated in her eyes, and she wouldn't have dared to date him back during the height of his Pussy Posse days.

Read on to find out about the beef between the co-stars.

They Hardly Spoke Between Scenes

Even though DiCaprio was Hollywood's newest 21- year-old heartthrob and soon-to-be leading man by the time he was cast in Baz Luhrmann's Romeo + Juliet, he still had a lot to learn. Who would be the first to teach him how it's truly done? 16-year-old Danes, of course.

Coming on to play Juliet, Danes wasn't fooling around. She was out to prove herself. Even though she was so much younger than DiCaprio, she was ten times more mature than him, and it equally shocked and impressed him.

She impressed him when she became the "only girl that looked me in the eye in auditions," DiCaprio said. She was also didn't flirt with him. Her seriousness was obvious to DiCaprio from the start.

DiCaprio told Vice, "I saw her television show, My So-Called Life, and I knew from that point on that she was just an extremely intense and emotional girl and possessed a lot of what we wanted to Juliet to be.

"We didn’t want a flowery, over-dramatic version of Juliet but somebody that was really forceful, because she actually laid down the law to Romeo and told him, 'If you’re so into me, you have to marry me and defy everything' and that was an important thing we wanted to bring up. As soon as I met with Claire and did auditions, everyone else was doing it the traditional way, and she like grabbed the back of my neck and kissed me. I was like, 'What’s going on here!' I was a little taken aback by the whole thing, but I realized she knew what she was doing."

Related: Leonardo DiCaprio Is A Vegetarian, But He Ate Meat For This Role

But DiCaprio's views on Danes, and her opinion of him in return, quickly changed when they started filming. According to multiple reports, it was tense between them, and they constantly fought because DiCaprio was somewhat of a prankster on set.

Remember, this was a time of frivolity in the young heartthrob's career. He was everyone's Romeo, and with the backing of his Pussy Posse (yes, the name describes them perfectly), he could virtually do any amount of shenanigans and still be loved by the masses.

Danes, being mature beyond her years, detested his immaturity on set. According to Showbiz Cheat Sheet, DiCaprio "tried to pull multiple pranks on Danes when the cameras weren't rolling, and the young actor wasn't having it."

In return, DiCaprio thought she was "too uptight." So they didn't get along at all and avoided speaking to each other between takes.

Related: How Close Are Leonardo DiCaprio And Johnny Depp Now?

The Telegraph wrote, they were "less 'star-crossed lovers,' and more just two very cross stars," while Showbiz Cheat Sheet wrote, "Danes was ready to drink the poison whenever she was around her co-star."

There Were Deeper 'Problematic' Issues

Years later, Danes revealed she actually had a crush on DiCaprio while filming. So much for trying to show him that his charms wouldn't fool her. But her crush was complicated.

After confessing her crush, Danes told W Magazine, "That was problematic. I couldn’t really have a crush on the guy I was professionally having a crush on! Quite a few gay men have talked to me about the fact that when they were kids watching Romeo + Juliet, they were confused about who they wanted to kiss. It was all about Leo! And I completely understand."

Related: An Inside Look At Leonardo DiCaprio's Luxurious Mobile Home

Despite her crush, her true feelings about DiCaprio's immaturity won in the end and led her to turn down another chance to work with him a year later on the film that would make his star skyrocket, Titanic. Danes revealed she turned down the part on Armchair Expert with Dax Shepard.

"I had just made this romantic epic with Leo in Mexico City, which is where they were going to shoot Titanic," Danes said. "And I just didn’t have it in me." While her heart was set, she said DiCaprio "was wrestling with the decision whether to do it or not."

"But he was like, ‘F— it, I gotta do this.’ And I looked down at him going like, ‘I totally understand why you’re doing that. And I’m not ready for that.’ And I think I really wasn’t ready for it," she said.

Danes said she has no regrets turning it down because watching the level of fame that DiCaprio received after looked "a little scary."

"I think I may have sensed that I was courting that [level of fame] or I was proximate to that," she said. "I just couldn’t do it. I didn’t want it. It was going to propel me to something I knew I didn’t have the resources to cope with. I knew I had to do a lot of foundation building."

It's okay because both Danes and DiCaprio were happy with their decisions in the end. Danes went on to build a foundation for her career while DiCaprio's settled into fame and got the female co-star he always wanted, Winslet, who let him pull a jacket full of his farts over her head and laughed with him about it. That's true friendship there. At least the Danes and DiCaprio can speak sweetly about working together now. Not going to lie though, we want to know what sort of pranks he tried to pull on her.

Next: Are James Cameron And Leonardo DiCaprio Friends?