Crystal called off her marriage to the Playboy founder earlier this year and went on to reveal intimate details about their bedroom antics together but Holly - who lived with Hugh as his girlfriend for years - thinks she was disrespectful.
The blonde beauty said: "I just think that once you break up with somebody, neither party should really talk about intimate details of the relationship. It's just rude and gross!"
She told America's Star magazine: "She can't think of anything on her own, so she has to do everything I've done. She needs to get her own identity for once in her life."
Crystal, 25, ditched the 85-year-old lothario less than a week before their planned wedding in June and has since claimed their lovemaking lasted "like two seconds".
She added: "Then I was just over it. I was like, 'Ahhhh.' I was over it I just like, walked away. I'm not turned on by Hef, sorry. He doesn't really take off his clothes. I've never seen Hef naked."