Rhys and Russell's on-screen chemistry spurred rumors that they were dating in real life.
Fans were assured their chemistry wasn't just the product of great acting but the result of their genuine attraction between the two actors.
And it was not just their followers. Their co-workers also believed the same.
Matthew Rhys and his potential wife Keri Russell at 2018 Emmys. (Photo: Twitter)
In an interview with Off Camera with Sam Jones, Russell recounted how her crew suspected their off-screen romance.
"We had to do a very explicit scene together," she recalled, adding that the director "was talking to the script supervisor. And he was like, 'well this might be kind of awkward and see how this goes.'"
"We kind of did it and just did it right away. And he told the script supervisor 'these two have definitely [expletive]'" she quipped, "he's like 'they're way too comfortable together.'"
Rhys and Russell had started dating in late 2013, but they kept their romance under wraps.
Their relationship eventually got confirmed when they welcomed their first child, son Sam, in May 2016.
Russell announced the arrival of their son during an appearance on the Today show.
