United Kingdom, Dec. 3 -- Sydney Sweeney is "obsessed" with Amanda Seyfried.

The 28-year-old actress stars alongside Amanda, 39, in The Housemaid, the new psychological thriller film, and Sydney admits that she loved working with the movie star.

During an appearance on The Tonight Show Starring Jimmy Fallon, Sydney shared: "Did I know Amanda before this? I'm obsessed with her. She knows how much I am with her. I am like the biggest Mamma Mia! fan."

The Hollywood duo previously sang along to ABBA's Angeleyes for a TikTok video, and Sydney loves that her co-star agreed to perform with her.

She said: "All my dreams came true! It was amazing."

Sydney revealed that she built a strong off-screen relationship with her co-star, and she descr...