Colin Farrell struck up an unlikely friendship with the screen legend Elizabeth Taylor, who died aged 79 in 2011, after meeting her manager at hospital in 2009, when his youngest son, Henry, was being born and Elizabeth was there to get a stint in her heart.
They subsequently both sent each other flowers and their relationship blossomed from there.
Speaking to talk show host Ellen DeGeneres, Colin said: "I got to have an audience with her, and that was the beginning of a year-and-a-half or two years of what was a really cool - which feels like in my head ... the last kind of romantic relationship I've had, which was never consummated."
Colin, 37, added he would call Elizabeth in the middle of the night and they would chat for hours.
He explained: "She wasn't much of a sleeper at night, like I'm not, so I'd call her at two o'clock in the morning ... and we'd talk for like, half an hour or an hour into the wee hours. It was really cool. I just adored her. She was just a spectacular, spectacular woman."
Colin, who also has another son, James, 10, with model Kim Bordenave, also joked he wanted to follow in the footsteps of Richard Burton and Conrad Hilton Jr. and marry the 'Cleopatra' actress, which would have made him her eighth husband.
He added: "I wanted to be number eight, but we ran out of road."
Elizabeth passed away in March 2011 from complications related to heart failure.