"I first heard the story of Harvey Milk when I was a closeted teenager. What I didn't know yet was that I would write the screenplay to tell that story," says Dustin Lance Black in the trailer for Mama's Boy. "And it changed the course of my life."

In 2009, he won the Oscar for Best Original Screenplay for Milk, which stars Sean Penn as the titular gay rights activist. He brought his mother, Anne, as his date, and recently shared with A.frame his most defining memory of the night: "I finally made it back into the theater and found my mom and put the Oscar in her lap, and just the tears. She was still crying, so I gave her a big hug and left the Oscar with her."

His relationship with his mom is now the subject of the Laurent Bouzereau-directed documentary, based on Black's 2019 memoir Mama's Boy: A Story From Our Americas. The film looks back at his upbringing in a conservative Mormon home and how, after he came out at age 21, Anne's devotion to her son despite the church's dogma eventually inspired his own activism.

"I've seen it and it was incredibly moving to me, but maybe that's not surprising. It's about me and my mom," Black told A.frame. "I've spent a fair amount of time over the years on the receiving end of the camera because of my political work, so I was prepared in that way. But nothing can prepare you for moving through your entire life story in about two weeks — and that's what we did. It was my mother's story more than mine, but from Lake Providence, Louisiana, to Texarkana, Texas, San Antonio, Texas, Central California, Los Angeles, and London, we scoured my mother's story and how it created a good troublemaker like me."

Mama's Boy debuts October 18 on HBO before streaming on HBO Max. Watch the trailer below.

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