Hugh Hefner's Son Cooper Bashes Holly Madison, Calls Her a Gold Digger

The drama between Holly Madison and her ex, Playboy publisher Hugh Hefner, now involves Hugh's 23-year-old son Cooper.

After the 35-year-old former Playboy Bunny made shocking claims in her new tell-all -- Down the Rabbit Hole: Curious Adventures and Cautionary Tales of a Former Playboy Bunny -- including that 89-year-old Hugh verbally abused her and offered her "thigh-opening drugs" when they first met, Cooper took to Twitter to slam her.

"How does a person who is famous for being a gold digger paint themselves as a victim of a relationship they aggressively sought out for?" Cooper tweeted on Tuesday.

WATCH: EXCLUSIVE -- Holly Madison Fires Back at Hugh Hefner's 'Rewriting History' Criticism

Hefner's youngest child also compared Holly to disgraced former Los Angeles Clippers owner Donald Sterling's mistress, V. Stiviano.

"Holly Madison, V. Stiviano, and a few other lovely ladies that lived in LA make a Justice League type group of wonderfully shi**y people," he tweeted.

Cooper isn't the only one on team Hugh. Kendra Wilkinson, Holly's Girls Next Door co-star, recently slammed her fellow Playboy Bunny, and acknowledged that the two former friends haven't spoken in years. She says Holly's claims are inspired by "revenge."

"Holly, you can tell, had this ulterior motive every minute being at the Mansion, and that motive was -- it was clear as day -- she wanted Hef's kids, she wanted a piece of Playboy and she wanted to marry Hef for, obviously, his will," Kendra, 30, told People. "We aren't sisters, we never were. We just dated the same guy at the same damn time."

ET spoke with Holly on Monday, when she explained her motives for the tell-all.

"It wasn't about having an ax to grind or wanting to get a reaction from him [Hefner], or, you know, inviting him back into my life in any way," Holly said. "I don't really care about his response. I wanted to share my story to inspire other women who might be in a bad relationship to get out, or not be branded by bad decisions they've made, and take charge of their lives and move on. ... I'm definitely not rewriting history. I'm finally telling the truth of my experience. For so many years I tried so hard to be a good girlfriend, and I cared about him and always had his back."

Hugh denies the claims in the book, telling ET that his ex has "decided to rewrite history in an attempt to stay in the spotlight."

WATCH: Kendra Wilkinson Reveals Whether She Actually Had Sex With Hugh Hefner

Watch the video below to see Holly explain why she didn't move out of the Playboy Mansion sooner if she had been treated so poorly.