This is why Diane Keaton and Al Pacino couldn't make it work

Did you know Al Pacino and Diane Keaton were once an item? Keaton, the idiosyncratic star of films like Something's Gotta Give and Annie Hall — the latter which nabbed her an Oscar and made her a style icon — and Pacino, legendary star of Scarface and Scent Of A Woman almost had it all. 

The two, who were relatively unknown actors at the time, met on the set of The Godfather in the early '70s, per InStyle. The classic film — often considered one of the best movies of all time — helped launch Pacino and Keaton's careers. However, their onscreen chemistry clearly translated to something else. The pair was "going to the mattresses" in a different sense. "I was really very taken with Al from the very beginning," Keaton told The Telegraph in 2013.

Keaton told People in 2017 that she was "mad for him [Pacino]. Charming, hilarious, a nonstop talker. There was an aspect of him that was like a lost orphan, like this kind of crazy idiot savant. And oh, gorgeous!" That being said, according to InStyle, the two didn't get together until filming had wrapped for The Godfather Part II. Howeverduring the production of The Godfather III, much like the film itself, the good just couldn't last. "For me the Godfathers, all three of them, were about one thing — Al. It was as simple as that," Keaton fondly wrote in her memoir, Then Again (via The New York Times). 

So what happened between Diane Keaton and Al Pacino? Here's a closer look at Keaton's ultimatum that ultimately led to their their demise.

Diane Keaton gave Al Pacino a marriage ultimatum

So what happened between Diane Keaton — who famously never married and has two adopted children – and Al Pacino, who has also never married but has "three children with two women"? Apparently, Keaton wanted the actor's hand in marriage while they were dating, and when he said no, the relationship was over. "I worked hard on that one. I went about it in not a perfect way," she told Peoplerecalling their fallout.

That being said, the pair have remained friends, and in 2017, Pacino gave a touching tribute to Keaton when she won an American Film Institute Lifetime Achievement award. His speech shows their friendship has withstood decades, even if their romance didn't. 

"I remember leaving the house once, and I had an interview," Pacino recalled during his speech, fondly sharing that the actress would often give him industry advice. "And I'm very uncomfortable here, of course, but at interviews, I'm even more uncomfortable, believe it or not," he said. "And she was very encouraging, helping me along, and I was leaving ... as I was leaving, she called out to me, she said, 'Al, you're going to be okay. Just remember, whatever you do, don't say you're an artist.'" He ended the speech: "I love you forever."

Aww! At least Keaton and Pacino seemingly stayed on good terms. However, just think about how many Oscars their children probably would have scooped up by now!