"My brother's just, like, untouchable," Stephanie said. "So I just don't understand why they give him so much love and support and value him so much more than they value me."
On Thursday's episode of the reality star's podcast, "Pratt Cast," Stephanie claimed her parents have always taken her brother's side and believes they may have even cut all ties with her.
"Things will never, ever be the same," Stephanie said. "For all I know, my parents have disowned me...That, and I've escaped a very dysfunctional family... It's really hard."
"My parents don't get that, like, they're rooting for the wrong kid, and it's always been that way," she continued. "Since I was, like, 18, it has always been my brother. He was never told to get a job. I was an intern in high school, then I worked in a clothing store, then I was a hostess at a restaurant. My parents were always on me. 'Get a job, get a job!' What was Spencer doing? He was playing in Malibu."
"The Hills" star also alleged her parents had her cover up the behavior of Spencer's wife, Heidi Montag.
"My brother's just, like, untouchable," Stephanie said. "So I just don't understand why they give him so much love and support and value him so much more than they value me that they actually had me grin and bear all the things that Heidi's done for the past 10 years to my family. I'm mad at my parents."
"I feel like I'm out of the jungle and I'm on a cliff looking down at it and they're still in the jungle, not having clarity," she added. "And seeing what they've been asking me to do is more than anyone can handle and especially in the public eye."
Stephanie also pointed out how no one in her family contacted her to wish her happy birthday on April 11, with the exception of her 11-year-old niece.
Earlier this week, Spencer said his relationship with sister Stephanie was like "living with this evil around me." In response, Stephanie clapped back at her sister-in-law.
"Well, you are married to the devil..." Stephanie captioned a screenshot of her brother's quote, which she shared on her Instagram Story Wednesday night.
Spencer is married to Heidi, and the two host a podcast called "Make Speidi Famous Again." During their April 15 episode, Spencer ripped into his younger sister.
"I'm just really trying to focus on [the] positive. It's so hard when so many people message you and keep bringing [it up]," he said of their rivalry. "It's like, 'I know, I know. I have been living with this evil around me for a long time.' I already know. Like, this is news to everyone else. I'm not getting in an argument with people that are just making up lies. If it's completely not truthful, it's insanity."
Stephanie previously dragged Speidi during an April 8 episode of her podcast, "Pratt Cast," telling Wells Adams and her listeners, "We are not on good terms. We are not on speaking terms. I do not consider them my family."
"I'm also not going to pretend that Spencer and Heidi are good people, like I was doing for most of the series for my parents," she continued. "For the shit they have done to me recently, I'm done. This is why I moved to London. I'm done. I cannot live near them. They are the most toxic people I've ever met. They are Bonnie and Clyde 'til they die, so if they say the sky is black, all of us are morons for saying it's blue."
She added, "If you ever have a son, Wells, I pray that he does not meet a Heidi Montag. What Heidi Montag does -- she has played my family for money. When my mom said, 'What do you want from Costco? Toilet paper, paper towels?' She said a treadmill."
Stephanie went on to say that the couple's true colors will show when "The Hills: New Beginnings" premieres in June. Replying to Stephanie's remarks on her own podcast, Heidi said the situation had been "very challenging and heartbreaking." She also implied that Stephanie's made "some very below-the-belt, nasty comments that weren't even true."
Spencer defended his wife of over a decade, adding, "If you think you're gonna walk on my sweet angel, Heidi, you have something coming your way."
"The Hills: New Beginnings" premieres Monday, June 24 on MTV.