Whoops!Cheradmitted she had to keep a close eye on her outfit to avoid a fashion mishap at Monday night’s premiere ofMamma Mia 2: Here We Go Againin London.

The star, who appears in the newMamma Miamovie as the grandmother toAmanda Seyfried’s character, wore a lacy bodysuit beneath a long black trench coat and wide leg pants, but according to Cher, the sheer undergarment wasn’t the one she was meant to be wearing that night.

“I am actually wearing the wrong bodysuit. They sent the wrong bodysuit!” Cher laughed on the red carpet during an interview withAccess Hollywood.

She added, “It is one size too small and I keep saying to everybody, like, ‘Amanda [Seyfried], Amanda [Seyfried], make sure my jacket is shut!’

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“Mamma Mia! Here We Go Again” - UK Premiere - Red Carpet Arrivals

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UK Premiere of Mamma Mia! Here We Go Again

“That doesn’t make any difference,” she said. “I was thrilled to death, and it was so silly. It was great fun, and I love her [Meryl], so it was perfect.”

Cher continued, “It was great, and she was hiding watching me sing, and I was so excited. I didn’t find out until afterwards—I would have been more nervous.”

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Mamma Mia! Here We Go Again World Premiere

In the follow-up to the 2008 adaptation, a pregnant Sophie (Seyfried) calls on the help of her mother’s friends and former bandmates Tanya and Rosie as she prepares for motherhood. As the film switches between the past and present,Lily Jamesstars as Streep’s character in her younger years.

Mamma Mia! Here We Go Againhits theaters Friday, July 20.

source: people.com