Holly Madison claims she constantly had intimate infections as a result of having sex with Hugh Hefner.
The 44-year-old beauty has accused the late media mogul of insisting they used baby oil as a lubricant, resulting in her feeling "constantly irritated", and even medical warnings not to use the greasy substance were not enough to persuade the Playboy mogul to stop.
Speaking on the 'Girls Next Level' podcast, she said: "Hef would use baby oil as lube. I do not recommend this. It is an infection waiting to happen.
"It's disgusting. I don't know what his hang-up was with it. It took it to the point where I was constantly irritated by this baby oil because it throws off your pH, so you're constantly going to have yeast infections.
"I remember talking to the gynaecologist about it and then telling Hef, 'You need to stop using baby oil. I can't use it,' and even telling him the gynaecologist agreed with me, and he would argue with me and be like, 'Well people use baby oil on babies.'
"And I'm like, 'Yeah, on their skin. Not internally. You're not supposed to put it there.'
"Then it got to the point where I would refuse to use it, but then other people would tell me that he would — in the bedroom — put it on his hand and then put it on me when my back was turned and I didn't know he was doing it.
"It was so foul and so non-consensual and so gross. I had forgotten about that for the longest time but I was reminded of it for some reason and it made me angry all over again."
Madison - who was one of Hefner's three main girlfriends in the mid-2000s along with Bridget Marquardt and Kendra Wilkinson - admitted the girls who lived in the Playboy Mansion viewed sex with the tycoon as a chore which they were keen to get over with "as quickly as possible".
She added: "He wouldn't move. He would be like a bump on the log in the middle of the bed.
'I can't explain to you guys how embarrassing that whole routine was...
"None of the females were into it, like sorry to burst the bubble."
Madison and Marquardt recalled how their former partner - who died in 2019, aged 91 - had a "hoarder-style" bedroom, which was always "messy".
Marquardt said: "We walked in and it was just a disaster in there. The lights were out, but there were two giant TV screens in there that were playing porn… There's just so much junk and vibrators all over the bed."
Madison added: "Imagine thinking you're this big player and you're bringing all these girls home, and your room looks like s***.
"It's like the weird eccentric millionaire version of the guy with the mattress on the floor and a 'Pulp Fiction' poster."