Stacey says growing up she and her younger sister, Courtney, were best friends. But she says that changed in high school when Courtney started hanging out with the wrong crowd.

TELL DR. PHIL YOUR STORY: Know someone with outrageous behavior?

“Courtney is a lying, stealing, manipulative bitch,” Stacey claims. “Courtney will lie, deny and cry until you have her backed into a corner.”

Stacey claims Courtney has taken jewelry, clothes and money from her and her parents and that she has even stolen Stacey’s son’s medication. She claims when Courtney stole her license, she was pulled over and arrested, and Stacey landed in jail. But Stacey claims the “craziest thing” Courtney has lied about is being pregnant on three separate occasions.

WATCH: Woman Says Younger Sister Blames Lying, Stealing, ‘Bad Behavior’ On Her Mental Illness

“A couple of months ago, she was pregnant for the third time, but there was just a few things that did not add up,” Stacey says. “The top part of the sonogram was cut off in the picture and I asked her why. She told me she couldn’t get an actual printout because insurance wouldn’t cover it. I knew it was [expletive]. Last week, she told me that she miscarried.”

Stacey says that at this point, she’s done having a relationship with her sister. “Courtney also claims that she has a mental illness. I feel like she uses her undiagnosed mental illness to justify her bad behavior,” Stacey says.

On Monday’s episode of Dr. Phil, hear from Courtney. How does she explain her behavior? Check here to see where you can watch.

TELL DR. PHIL YOUR STORY: Dr. Phil, please solve our conflict!

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