Diane Keaton says she starred in Justin Bieber’s “Ghost” video “It was one of the most enjoyable experiences of my life.”

Justin Bieber seriously fascinated Diane Keaton.

In a preview of the episode “The Ellen DeGeneres Show” on Monday, Keaton talks about sitting with Ellen for the 20th time and working with the singer in a video of the song “Ghost.”

Read more: Watch Diane Keaton live it with Justin Bieber in his new music video

“It’s so weird,” she laughs, after the video clip plays.

Asked if it was fun to star in the video, Keaton said: No, he is a wonderful person. Youth! Gorgeous and genius. “

“It was one of the most enjoyable experiences in my life,” she adds.

Ellen also surprised the singer in an episode of the 2015 show, playing a clip when she actually introduced Keaton and Beaver.

“It was fun,” Keaton recalls. “I liked it. He’s totally adorable.”

Read more: Reese Witherspoon calls on Diane Keaton for confusing Leonardo DiCaprio with her son Deacon

Also at the show, Ellen lets guests play the game “What is Diane Keaton?”. In this game, the star needs to remember the trivia about her previous 19 appearances.