The Bad Boy founder is being sued by a woman named Ashley Parham, who claims Diddy sexually assaulted her in a gangbang-style rape after she dissed him on a FaceTime call.

According to the lawsuit, obtained by TMZ, Parham met a friend of Diddy's at a bar in February 2018, and he called Diddy on FaceTime ... but Parham says she wasn't impressed by the man's famous friend, telling Diddy to his face she thought he played a part in Pac's death.

Parham claims Diddy told her she would "pay" for her Tupac comment and overall dismissal of him ... and she says one month later Diddy's friend set her up for Diddy to rape her.

In her suit, Parham says the man she met at the bar invited her over to his Orinda, California home ... and when she was there Diddy showed up and told her "she thought she would never see him in person." She says Diddy held a knife to the side of her face and told her he would give her a "Glasgow smile" in retaliation for her Tupac comments.

Parham claims Diddy's top consultant, Kristina Khorram, was there too, and KK told Diddy not to cut Parham's face because they could "sell" her to potential clients for sex. Parham claims KK then threatened to ship her off anywhere in the world, never to see her family again.

In the docs, Parham claims Diddy took off her clothes, removed the knife from her face and then got a bottle of liquid from a large fanny pack and covered her body in a liquid substance. She says Diddy and KK tried to insert something into her vagina that they referred to as an 'IUD,' but it malfunctioned, and then Diddy picked up a TV remote and violently inserted it into her vagina, using the remote to violently rape her.

Parham claims Diddy told her that her life was in his hands and that he could "take her" and she would never be seen again ... and then he later violently raped her anally, and instructed two other men to do the same, which she says they did. She also claims another man with Diddy raped her vaginally.

After the alleged gangbang-style rape, Parham claims Diddy and his buddies left her limp body inside the home as they went in the backyard to smoke weed and cigarettes. She says when she finally regained her bodily functions, she grabbed a knife and an oversized shirt and tried to leave, but had to get past Diddy to reach the exit. She says she confronted Diddy, who she says was surprised to see her walking because he had given her "enough drugs to take out a horse."

Parham claims Diddy told her he "hadn't had any a** that tight in a while" and offered her money and told her to say everything was consensual. Parham says she refused and threatened to go to the cops, with Diddy telling her no one would believe her, and if she told anyone he would harm her family. She says one of his associates showed her a phone that appeared to be live-streaming video from outside her sister's home.

In the suit, Parham claims Diddy even called his mom, Janice Combs, in an effort to convince her not to report the rape ... and she says Diddy's mother yelled at her to not hurt her son, and brushed off Parham's claims Diddy raped her.

Parham claims Diddy told her he'd gotten away with bigger crimes and again referred to Tupac. She says the Tupac comment pissed off one of the men who was with Diddy, who drew a gun and later fired a shot that sent Diddy running.

She says she then chased after Diddy with the knife, caught up to him and was about to stab him when he started pleading for his life. She says she had a moment of clarity and ran for the exit, but Diddy chased her down and she wielded the blade at him, grazing his abdomen.

In the docs, Parham claims she escaped to the street and yelled for neighbors to call the cops ... she then heard Diddy's SUV speeding away from the home.

Parham claims a sheriff from the Contra Costa County Sheriff's Department responded, and she told him she had been violently gangbanged by Diddy and others ... but she doesn't believe the CCCSD investigated her claims.

She also says she reported the rape to Walnut Creek Police and the Orinda Police Department ... but was told no law enforcement agency had opened an active investigation into any of her reports.

Parham's attorneys in this lawsuit are Ariel Mitchell and Shawn Perez ... so this is separate from the 120 sexual assault lawsuits Texas attorney Tony Buzbee says he's filing against Diddy.

In response, Diddy's camp tells TMZ ... numerous lawsuits -- many of them by unidentified complaintants -- have been filed against Diddy in recent months with claims "spanning from the false to outright absurd."