Lena Dunham Cheated on Ex Jack Antonoff, New Memoir Reveals

And they also arranged a clandestine hookup at her parents’ house when they were out of town. 

“Nick met me at their place, where he went down on me while I watched the steady flames hiss in the electric fireplace,” she wrote. “Afterward, we took a bath, washing each other’s hair at the same time, then f–ked again on top of my parents’ quilt. He looked deep in my eyes as he moved over me and said: ‘You’re making me want to cut the brakes on your boyfriend’s car.'”

But when Jack, 42, finally returned home from tour, Lena found herself settling back into her old ways. She detailed crawling into bed with him after another rendezvous with Nick, hoping that the affair would somehow help restore her broken relationship.

“I tried to calm my sheer terror by telling myself I was finally home from a bad dream,” she wrote. “I had fixed myself, proved I could be the freaky sexy lively young woman he fell in love with. I had exorcised the demon. In a way, I had f–ked Nick for both our sakes, to make our house a home again. It would all be better now. I fell asleep to the rhythm of Jack’s breathing, like I had been doing for almost six years.”