The trainwreck of a relationship between Courtney Stodden and mom Krista Keller just keeps getting worse.

In an exclusive sneak peek clip at this week's "Mother/Daughter Experiment: Celebrity Edition," the reality TV star accuses her mother of hitting on another guy who was interested in her ... when she was just 12!

"Doug [Hutchison] isn't the only guy you've been emotionally attached to," Court says during a therapy session. "I was 12-years-old and there was this grocery store bagger who was 17-years-old. I think you were attracted to him."

Krista doesn't deny it -- and Kim Richards' reaction is priceless. Check it out above!

"I felt like you used me to get him over to the house," Stodden continues.

While the clip is cut up a bit, Krista starts talking about feeling "empty" in her marriage to Courtney's father. "I was emotionally, completely empty."

Kim isn't the only one who is a little shocked by the conversation.

Costar Natalie Nunn calls out Courtney for "disregarding" everything her mother says -- and says she's surprised to see Stodden stand by her much older beau.

"If my mother told me my husband and her had some emotional situation going on, I would not be sitting here still married to my husband," she tells her flat out. "I’m just gonna say that straight up."

In a confessional, the "Bad Girls Club" star then says, "I'm trying to figure out who was playing just the tip."

We'll see if the situation between Stodden and Nunn escalates when "The Mother/Daughter Experiment: Celebrity Edition" airs Thursday on Lifetime.

For more on Courtney's troubled relationship with her mom, check out our exclusive interview below:

Hot Videos