Spoiler alert! We're discussing minor details about the plot of John Krasinski's PG-rated family film "IF" (in theaters now).

“IF” is indisputably the starriest movie of the year, with vocal cameos from Matt Damon, George Clooney, Jon Stewart and nearly two dozen other celebrities.

But the person who shines brightest is Tina Turner, whose music is featured prominently throughout the kid-friendly adventure. When we first meet Bea as a young girl (Audrey Hoffman), she’s dressed up as Turner and putting on a living room concert for her adoring mom (Catharine Daddario) and dad (John Krasinski).

Years later, after her mom’s death from cancer, 12-year-old Bea (Cailey Fleming) has lost all sense of joy and wonder. That changes when she meets a group of misfit imaginary friends (known as IFs), who are exiled to a “retirement home” under New York’s Coney Island when their kids grow up and forget about them. Bea offers to help and lift their spirits, culminating in a euphoric dance number set to Turner’s “Better Be Good to Me.”

John Krasinski wanted Tina Turner's 'Better Be Good to Me' to be an 'anthem' for the 'IF' movie

The soaring anthem, which peaked at No. 5 on the Billboard Hot 100 singles chart, is taken from Turner's 1984 comeback album “Private Dancer.” Krasinski, who also wrote and directed “IF,” wanted to use the song as a tribute to his mom, Mary, who is a major Turner fan.

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“I remember vividly dancing in the kitchen with my mom to Tina Turner,” Krasinski recalls. “There’s something so emotional to me about sharing music intergenerationally. That’s something that was really special to me and that I really wanted to be in the movie. I love the idea that it's not a song you would think this girl would love, but she loves it because of the people she loves.”

Turner died last May at age 83 after a long illness. To get the rights to use her song, Krasinski wrote directly to the eight-time Grammy winner’s estate, sending them the scripted scene and offering to get on Zoom to pitch the number.

“The first thing I did was write an email saying that this is the heart and soul of the movie,” Krasinski says. “Tina’s song is basically the anthem for imaginary friends. (The IFs) are the ones saying, ‘Better be good to me and don’t forget me.’ Her song was the absolute perfect one for our movie, and they got it. They were so understanding and so supportive, I can’t thank them enough.”

Taylor Swift fans should look out for this Eras Tour Easter egg with Ryan Reynolds

In the dance number, Bea and the imaginary friends re-create the “Better Be Good to Me” music video. The scene was shot over two days with Fleming, 17, and a bunch of dancers wearing motion capture suits. Ari Groover, who played Turner in Broadway's "Tina" musical, also makes a brief appearance as the rock legend.

“I had so much fun,” says Fleming, who knew of Turner before the movie but didn’t know her catalog.

The actress' enthusiasm for Taylor Swift also found its way into "IF." Toward the end of the film, Bea is walking up the street with her new friend Cal (Ryan Reynolds). Moviegoers can only hear the tail end of their conversation, in which they excitedly discuss wearing bracelets all over their arms.

That is, of course, a reference to the pop star’s blockbuster Eras Tour, where fans frequently trade Swift-themed friendship bracelets. Reynolds has attended the tour multiple times with his wife, Blake Lively, who is also Swift's close friend.

“John told us when we were shooting that scene that there was no dialogue and the audience couldn’t hear us, so it didn’t matter what we said,” recalls Fleming, who has tickets to attend the Eras Tour for a second time this fall. “So I started talking about Taylor Swift, because that’s my default topic, and it wound up making it into the movie. I love her.”