Glamorous actress Amanda Seyfried may look like butter wouldn’t melt. But her choice of tattoo tells a different story.

The American actress who shot to fame in the film version of musical Mamma Mia has revealed a surprising choice of inking.

Seen on her left foot at Tuesday’s premiere of new film Dear John, Amanda revealed a tattoo of the word ‘minge’ on her left foot.

The actress revealed her Mamma Mia! co-star Colin Firth was the inspiration for the unusual tattoo.

She told Glamour magazine: ‘…Colin Firth used to say that word on set and Rachel (McDowell) had to explain to me what it meant.

‘So it’s on my foot. It’s to make me laugh, and every time I look at it I do.’

Amanda and best friend Rachel McDowell, who was in Mamma Mia! both have the matching tattoos.

‘I’ve never really been a fan of tattoos but I wanted to see what it felt like. Rachel has a lot of them.’

Seyfried added: ‘I have a dirty sense of humour. I can be blunt and vulgar.’

Despite the tacky tattoo, Amanda, 24, still looked stunning in a glittering LBD as she cosied up to heartthrob and Dear John co-star Channing Tatum at the Kensington Odeon in West London.

The pair star in the movie version of the novel by acclaimed best-selling author Nicholas Sparks.

The low-budget film surprisingly knocked Avatar off top spot in the U.S. box office when it was released in February.