Heather Thomson has come out with quite the allegation against Sonja Morgan.

And not only is it lit.

It's also pretty darn vile, if you ask us.

In Dave Quinn’s revealing new tell-all book, “Not All Diamonds and Rosé: The Inside Story of the Real Housewives from the People Who Lived It,” Thomson claims that her Real Housewives of New York City co-star allowed men to “put lit cigarettes in her vagina.”

Trust us.

We really wish we were making that up.

And we apologize for any imagery the mere reading of that sentence may have forced you to conjure up.

Thomson, however, shared details of the alleged incident in a section of the aforementioned tome that focses on The Real Housewives of New York City Season 7 cast trip to Atlantic City.

As a quick refrsher:

Morgan made Thomson and co-star Kristen Taekman wait in the lobby of her famous townhouse back then... as she prepared to meet them downstairs to get into a limo taking the ladies to New Jersey’s tourist destination.

Not scandalous just yet, right?

“That’s actually when I turned on Sonja, because I had literally carried that woman home,” Thomson told Quinn.

She added in this interview, which made its way into the book:

“I had scraped her off carpets. I had taken her out of a vestibule where she was letting guys put lit cigarettes in her vagina.”

We're sorry, but... COME AGAIN.

“I had done so much for that woman," Heather went on.

"And here we are, waiting to go to Atlantic City. We all arrived at her house, but the limo wasn’t there yet. And it was raining out. Well, she would not let us in."

Morgan has yet to respond to this whole cigarette/vagina accusation.

However, the fashion designer did explain why she never came down to check on Thomson and Taekman, who were just hanging out in the front entrance of her residence.

“I was upstairs, and my sister called me to tell me someone we knew had died,” Morgan says in the same section of the same book.

“She was supposed to come take care of my daughter [Quincy], but because of this death, she couldn’t.

"I didn’t have a housekeeper and I had my daughter there who doesn’t film … anything could go wrong.”

Morgan said she didn’t want to leave her then-teenage daughter alone as she “could be kidnapped.”

She went on to say that Thomson was “fake” when she “decided to come in and film and say, ‘We’re outside and we’re freezing.’”

Thomson and Taekman eventually entered Morgan’s home against her wishes, a move that incensed the latter Bravolebrity.

“If the situation were reversed, I wouldn’t go running through Heather’s house,” she said. “Wait in the f—king car! Rudeness! And they spilled coffee on my gold-inlay family table.”

Thomson and Taekman both left this franchise after the 2015 season aired.

For her part, Morgan has appeared as a full-time cast member since Season 3.

The latest season, however, ended with so much tension between cast members that the reunion was scrapped and questions now abound about the show's future.