Elliot Page is sharing a lot in his new memoir.

In "Pageboy," the star writes that he "was taken aback the moment" he saw "Juno" co-star, Olivia Thirlby.

At the time, he was portraying a pregnant teen girl in the 2007 independent film.

Page came out as gay in 2014 before announcing he is transgender in December 2020.

In his memoir, Page writes that Thirlby was "the first woman I had a suitably consensual sexual relationship with."

"We were the same age, but she seemed so much older, capable, and centered," Page, who was 20 at the time, writes. "Sexually open, far removed from where I was at the time. But the chemistry was palpable, it pulled me in."

Thirlby "had much more experience," Page said, and the pair "became friends quickly, spending a lot of time together."

Things became intimate, Page writes, after Thirlby announced, "I'm really attracted to you," and Page responded likewise.

"What were we thinking? We thought we were subtle. Being intimate with Olivia helped my shame dissipate. I didn't see a glint of it in her eyes and I wanted that -- done feeling wretched about who I am."

Thirlby first spoke publicly about being bisexual in a 2011 interview with Brooklyn Magazine.

In 2014, she married Jacques Pienaar whom she met on the set of the 2012 film, "Dredd."

CNN has reached out to reps for Thirlby for comment.