Sara and Erin Foster Had 'Deep' Resentment as Dad David Foster Raised Brandon and Brody Jenner

The Foster sisters are opening up about their complicated family dynamics.

During an interview with Oliver and Kate Hudson on the latest episode of their Sibling Revelry podcast, Sara and Erin Foster reflected on their upbringing after dad David Foster and mom Rebecca Dyer divorced in 1986.

David, an extremely successful music producer, went on to marry actress Linda Thompson, mom to Brandon and Brody Jenner with her ex Caitlyn Jenner.

“Our dad was raising other children,” said Sara, 38, explaining that she and Erin, 37, grew up with their mom. “He wasn’t raising us. He was raising Brandon and Brody.”

“I was, like, dealing with my whole own emotional turmoil, which was watching my father raise other children,” she said. “That was the thing that kept me up at night.”

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Explained Erin, “We never lived with our dad after our parents broke up. So from the ages of 3 and 5, we were living with our mom, and our dad was living in this $20 million house with Brandon and Brody. It had the trolley, it had the pool.”

“They had like, four cars,” Sara chimed in.

“They had a very different life,” Erin acknowledged. “But out in the world, people would be like, ‘You guys are spoiled brats and you guys have it all and you’re rich kids.’ And we would be like, ‘I mean, yeah, but we don’t live there. We don’t have the gate code. We don’t have a room there. We’re not really a part of that world.'”

“Listen, we grew up with a safety net. Our dad always said to us, ‘You’ll never be homeless and you’ll never be hungry,'” Sara said. “But we did not have a trust fund … we had to have a job.”

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Asked if they had “resentment” at the time, both agreed, “Oh, deep. Oh, of course.”

“Mine was less resentment toward them, it was more like, we’re misunderstood out in the world, because we have this fake, spoiled lifestyle, but we’re not even really allowed to be a part of it,” Erin said. “So we get all the backlash for it, but we don’t actually get the benefits. And I think when you’re 15, you don’t have the maturity to understand that them having a spoiled lifestyle is not going to serve them well. You’re just like, ‘Why do they have all these things that I don’t have and my dad’s the one giving it to them?'”

The situation affected Erin and Sara’s relationship at the time, the sisters said.

“Sara being mean to me was because she was going her own s—,” Erin said. “And she didn’t have room or space to be a big sister.”

“That’s a good way of putting it — there was no room or space,” Sara admitted. “I had so much of my own inner turmoil with our own family dynamic. But you look back and you’re like, ‘Oh my God, we’re each other’s allies.'”

“And one thing our dad always did say was the most important thing to him was that we would cultivate a deep, meaningful connection with each other as siblings,” she added. “He would say, ‘That is all you have in life.'”

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Erin, who got engaged to businessman Simon Tikhman in August, said the differences in her and her fiancé’s upbringings were obvious early on.

“I am now engaged to someone whose parents have been married for 40 years. He comes from a Russian, Jewish culture that’s a thick community of family-oriented people,” she said. “Very early on in our relationship, I realized this disconnect in our upbringing, because he was like, ‘Erin, the number one rule in life is you always honor your parents.'”

“And I was like, ‘Honor your parents?!'” she exclaimed. “I had to, like, completely rebel against my parents to survive. … To survive, I had to basically tell them what I’m going to do, or else I would have been stuck in Malibu.” (She left Los Angeles for a year to go to high school in Switzerland.)

David and Thompson, 69, ended up getting divorced in 2005. He went on to marry Yolanda Hadid, 55, in 2011; the two split in 2015 and the divorce was finalized two years later.

David, 70, is now married to Katharine McPhee, 35. They tied the knot in June.