United Kingdom, Oct. 12 -- Al Pacino reportedly "regrets" not marrying Diane Keaton.

The late actress - who died aged 79 on Saturday (11.10.25) - previously said she had a "crush" on the 85-year-old actor when they filmed The Godfather together in 1971, but things did not turn romantic until they were making 1974's The Godfather 2.

Keaton and Pacino - who played a couple, Michael Corleone and Kay Adams-Corleone, respectively, in the films - had an on-and-off relationship from 1971 to 1987 before they split in 1990 because he would not commit to marriage.

A pal of Pacino's told MailOnline: "Looking back, Al admits the love of his life was Diane who he's always called, 'an amazing woman'.

"I know he will forever regret he didn't make hi...