Holly Madison reveals some shocking things about her ex-boyfriend, Hugh Hefner, in her new memoir titled, ‘Down the Rabbit Hole.’ Among them? Hef allegedly used to watch porn, smoke pot, and jerk off while his girlfriends fooled around with each other in his bedroom.

In her new memoir, Holly Madison, 35, spills all the X-rated details of her sex life with ex-boyfriend Hugh Hefner, 89. In the pages of Down the Rabbit Hole: Curious Adventures and Cautionary Tales of a Former Playboy Bunny, Holly recalls how she was rarely alone with Hef during sexual encounters, and all the girlfriends took turns having intercourse with the Playboy owner, but he “always finished by himself.”

Holly says Hef would watch porn, smoke pot, and masturbate while his girlfriends, and whoever else was in the room, pretended to get it on around him. They liked to call it a “fake f***,” according to Holly. Holly’s first time in Hef’s bedroom happened after a night out with “roughly a third of a bottle of vodka sloshing around in my stomach.” “There was zero intimacy involved,” she says. “No kissing, nothing. It was so brief that I can’t even recall what it felt like beyond having a heavy body on top of mine.”

Holly also said playmates liked to “f***” celebrities behind Hef’s back at mansion parties. She also spilled secrets on Kendra Wilkinson, suggesting that her husband Hank Baskett was into another playmate before her!

After reading Holly’s disses in her new book, Hef is furious, HollywoodLife.com has EXCLUSIVELY learned. “Hef is furious over Holly’s betrayal. He knew she was upset over the way things worked out, but that’s part of life. Hef gave her this amazing opportunity and they had a lot of fun together. She was never complaining about their love life or their relationship when she lived there. If she was unhappy, she should have said something or just left. No one held a gun to her head and said she had to stay,” a source tells us.

Hef does have a point — Holly dated him between 2003 and 2008.

What do YOU think, HollywoodLifers? Should Holly have kept her sex life with Hef private? Vote in our poll and tell us how you feel!

— Chris Rogers

Follow @ChrisRogers86