Sophie Turner and Maisie Williams played sisters on "Game of Thrones" and are real-life best friends.

But while filming the megahit HBO series, the crew thought the two women were actually in a relationship and according to Turner, they loved adding to the speculation.

The 23-year-old actress told Conan O'Brien on his talk show that, "We fully knew about it, we played into it."

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"So, on the set, we would kind of do the scene [and] then try and kiss each other in the middle of the scene and see if anyone would react," she teased.

"And it's 'Game of Thrones' so incest is so normal that they were like, 'Alright, that's fine'. It was probably the most tame thing that happened on the show, actually," the "Dark Phoenix" actress joked.

She and Williams' bond grew over the course of filming the show and growing up on TV together. Turner told Dr. Phil on his podcast "Phil in the Blanks" that Williams is only a year younger than Turner and they had so much in common, the friendship came naturally.

"She was my best friend, and she was the only one I really told about all of it," she explained. "Maisie and I used to do it [stay inside] together. I think being friends with each other was quite destructive because we were going through the same thing."

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"We used to get home from set, go to a Tesco across the road, a little supermarket, and just buy food. We'd go back to our room and eat it in bed. We never socialized for a couple of years. We didn't socialize with anyone but ourselves," she revealed.

In a recent interview, Turner confessed that during last few seasons, she and Maisie had sleepovers all the time.

“We just used to sit there and eat and watch stupid videos and smoke weed,” she told Vulture. “I don’t know if my publicist will kill me for saying this. We’d get high and then we’d sit in the bath together and we’d rub makeup brushes on our faces. It’s fun.”