Shirley MacLaine: One of my best love affairs was with a Canadian driver

Shirley MacLaine may have once slept with three men in one day, but there is only one man who holds a special place in her heart (and bed).

In a new interview with the UK's Guardian around her upcoming guest stint on "Downton Abbey," the 78-year-old actress admitted her greatest lover was a Canuck.

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"One of my best love affairs was with my driver," she said."He was Canadian. We had the best time."

MacLaine admitted that her celebrity, which reached a fever pitch in the '60s when she starred in classic comedies like "The Apartment" and "Irma La Douce," caused a rift in their relationship.

"He was too intimidated by my fame," she told the newspaper. "I don't know how any guy could have put up with me, really."

Last year the Oscar-winning star of "Terms of Endearment" caused a stir when she opened up to Oprah about her three-decade "open marriage" to producer Steve Parker, with whom she was married until 1982.

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Though she is currently single, MacLaine recently told the UK's Radio Times that she thinks she was "lovers" with her "Downton" co-star Maggie Smith in "another life." On the British series, which airs in Canada on PBS next year, MacLaine plays abbey wife Cora's mother, Martha Levinson, who faces off with the famously sharp-tongued Dowager Countess (Smith).