Ewan, 46, and 32-year-old Mary Elizabeth are said to have spent over an hour at The Good Life Eatery in St. John’s Wood, North West London, with the pair “deep in conversation” before they both left on Ewan’s motorbike.
Speaking to The Sun, one witness explained: “Ewan and Mary Elizabeth were there together and seemed relaxed in each other’s company.
“There’s always lots of celebrities around in that area. The cafe was really busy and have to go to the counter to order food, so people are up and down constantly.”
The publication has also obtained photos of Ewan kissing Mary Elizabeth in the diner, with the pair starring in US TV show ‘Fargo’ together.
American actress Mary Elizabeth split from her husband Riley Stearns in May of this year, however, Ewan has been married since 1995 and has four daughters.
Despite not publicly announcing a separation, he and his wife, Eve Mavrakis, have recently been spotted without their wedding rings, prompting speculation that they may not be together any more.
Mary Elizabeth and Ewan play lovers in FX’s TV crime drama, with both joining ‘Fargo’ for its third series and filming on location in Calgary, Canada.
Announcing her split from her childhood sweatheart five months ago, Mary Elizabeth insisted that they remain “best friends” and that she will “always” love Riley.
However, in June Riley raised eyebrows when he closed his Twitter account after tweeting: “Keep almost tweeting stuff I shouldn’t so I am saying bye for a while.”
Yahoo Celeb UK have contacted Ewan’s reps for comment.