The 23-year-old actress – who played Sansa Stark in all eight seasons of the HBO fantasy epic – admitted the team did such a good job casting her double Megan Parkinson that they even fooled her husband when he was visiting the set.
Speaking on ‘Nova’s Smallzy’s Sugery’, she said: "On ‘Game of Thrones’ actually, I had a photo double that people would do double takes at because she looked so much like me.
"It was insane. Even Joe went up to her at one point and tried to give her a kiss and he was like ‘Oh, Sorry! Sorry, it’s not Sophie, wrong one!’ "
However, Sophie revealed it wasn’t an issue while she was filming ‘X-Men: Dark Phoenix’, and she insisted they avoided an awkward moment with her stunt double.
She laughed: "They don’t really look like me. First of all, they are much fitter, have much more muscle and just better looking aesthetically in general."
Meanwhile, Sophie has also admitted she and co-star Maisie Williams – who played her on-screen sister Ayra Stark on ‘Game of Thrones’ – used to play tricks on the crew by trying to lock lips in the middle of their scenes.
She recently said: "We fully knew [that people thought we were together]. We played into it. We did. So on the set, we would kind of do the scene then try and kiss each other in the middle of the scene and see if anyone would react."
The blonde beauty also insisted the kisses were just jokes to make people believe she and the 22-year-old star were dating.
She added: "Yeah, you know, sometimes you just wanna make out with your best friend."