Anne Hathaway more than credibly teams with internet heartthrob Nicholas Galitzine for “The Idea of You,” an age-reversing rom-com.

Instead of the decades older guy finding purpose and passion with a dewy-eyed 20something, “Idea” finds Hathaway’s divorced mother of a 16-year-old daughter having a passionate, life-changing affair with Galitzine’s 24-year-old boy band singer Hayes Campbell.

Hathaway, 41, had no trouble embracing this comedic/dramatic premise.

“I had Anne in mind from the very beginning,” revealed producer Cathy Schulman during a virtual LA press conference. “She was the first person who read it and said yes. We wanted to take the character from Robinne Lee’s book, a woman that she felt could be any of us.”

“I received lots of romantic scripts in my 20s,” Hathaway recalled. “In my 30s I focused on motherhood” – two sons with husband Adam Shulman – “and having this rich personal life. So I didn’t notice I hadn’t been sent romantic scripts in a long time.”

Then came “The Idea of You” with “such a beautiful character in an amazing world. Why,” she wondered, “do these stories stop?

“One of first conversations I had with Cathy,” she continued, “was that I’m 39 and was turning 40 when filming and without designing it, it became so personal.”

Key was Galitzine’s lead singer for the fictional August Moon boy band. London-born and 29, Galitzine has made a career out of making pulses quicken, from teen films like “Handsome Devil” and growing into roles like a gay British prince in “Red, White & Royal Blue.”

In “Idea of You,” Galitzine’s Hayes must possess the maturity and worldliness to handle major media attention when his “older woman” becomes social media fodder.

But it wasn’t enough to just play opposite revered film royalty like Hathaway, he had to sing, dance and command a concert stage as well.

“The dancing and performance was tricky because I’d never done it before. But for the human side of Hayes, which was the side I was most interested in, I had a wonderful partner.”

As to how they created the chemistry that sees “Idea” spin its magic, “We’ve been asked this a number of times,” Hathaway acknowledged.

“We’re both very playful people and established a friendship. It doesn’t feel like work at all.  I’m just happy to have made friends with a wonderful person who’s so talented and has so much ahead of him. I knew he was there with me step for step. We always kept it light with each other.”

“It’s funny,” Galitzine reflected, “so much onus gets placed on ‘chemistry.’ But it’s not something you’re building to create. It just flows.”

“The Idea of You” streams on Prime Video May 2.