While walking the red carpet at the London premiere of her new film, Mamma Mia! Here We Go Again, the legendary actress spoke with ET about how much fun she's having on set of the HBO show.
ET spoke exclusively with Streep at the London premiere of her new movie musical, where she dished on working with the iconic singer and teased her upcoming role on 'Big Little Lies.' 'Mamma Mia! Here We Go Again' hits theaters on July 20.