Dakota Johnson had to 'superglue thong’ to her body while filming 50 Shades of Grey sex scenes

If anyone is still thinking about 50 Shades of Grey, Dakota Johnson once said that she had to glue a thong onto herself while filming one of the movies.

What started as Twilight fan fiction and morphed into one of the best selling book series of all time also ended up becoming a trilogy of films starring Dakota Johnson and Jamie Dornan.

Financially, the 50 Shades world has been a staggering success, less so critically but everyone involved can dry any tears they have with the massive piles of money they've made off being part of it.

Filming such an erotic series of books is a challenge in and of itself, as there's lots of sex to be translated from the page to the screen and the actors have got to be properly safeguarded throughout the entire process.

The films made an awful lot of money (Stephane Cardinale - Corbis/Corbis via Getty Images)

Dornan said that 'you do know what you are getting into' when you sign up to do those movies and he spent a lot of time pondering whether or not to take the job on the 50 Shades movies.

Both lead actors had to take steps to preserve their modesty while filming those scenes.

Speaking to Marie Claire, Johnson explained how she was sticking her clothes onto her for filming during the movie.

Johnson said: "I had these sort-of strapless thongs that had glue on them. It's not glue, but it's sticky. They're, like, basically if it were a nipple pastie, but underwear.

"But it's only sticky at the top, it's not sticky the whole way.

"It would also come off because the adhesive would wear out, so then they would superglue it to my body so that it wouldn't fall off."

The film came out over a decade ago now (Chuck Zlotnick/Universal Studios)

Honestly, the lengths these actors had to go to make the film work.

Speaking of lengths, Dornan had to make sure his was kept safely within a 'wee bag', as he told GQ that: "Your dignity is intact as much as it's all tucked away in a little flesh-coloured bag.

"As a guy you put all your essentials in a little bag and you tie it up like a little bag of grapes and it's tucked away. It’s quite a peculiar thing to do every day."

One can only imagine, though perhaps one ought not to.

Dornan later stressed that the 'wee bag' was just an expression and that just because he called it that 'doesn't mean it's actually wee in size', saying that in his case it was 'quite a big bag'.