Watch Tori and Zach Roloff Discuss Fears for Son Jackson, 5, as He Discovers Dwarfism Diagnosis

Zach Roloff is getting candid about the concerns he has for son Jackson as he gets older.

In an exclusive clip shared with PEOPLE from an upcoming episode of Little People, Big World, the dad of three talks with wife Tori Roloff about how their oldest, son Jackson Kyle, 5, is getting to the age where he'll soon realize his differences from his peers.

Zach and all three of the couple's children live with achondroplasia, the most common form of dwarfism, while Tori is of average height. In a conversation with Tori, Zach explains he's recently been thinking about how Jackson will be affected by the realization of his dwarfism, with his wife admitting she also thinks about when that moment will come.

"When it comes to Jackson being different, I don't think he's caught on yet. We haven't had the talk yet, about how we're different than everyone else," Zach explains in a confessional with Tori.

At a recent Little People of America (LPA) convention Jackson said that the others "look just like" his dad, though Tori explains she doesn't think Jackson knows he looks the same way.

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Tori Roloff/instagram

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"I think he's gathered it, I just don't know if he's gathered it enough to personify himself as that," she says. "I think he's gathered that, 'these people are like dad and grandma and grandpa, but they're not like me.'"

Back in their conversation as the couple watches Jackson play, Zach expresses "worry" about how Jackson is going to process the realization.

"I worry about how he's so proud of himself and has such confidence in himself and sees himself so highly, I hope that that doesn't break him down," he says.

"I think we have to continue to foster that as best we can," Tori replies.

Monique Serra

In a solo confessional, Zach continues his thoughts. "I hope he doesn't lose it but it's also super sad when you have such confidence in yourself and then eventually it will catch on to him."

Noting that it's "part of the sad thing" about being a little person, Zach says that after a while you come to realize, "'Wow, I'm being left behind,' and you can't catch up."

Drawing on his own experience growing up, Zach explains, "I went through it. There's no real one big moment I had where I was like 'Oh wow, I have dwarfism.' It's like little moments that kind of accumulate, racing at school or playing chase."

TLC

Recalling friends would "run away from" him, Zach gets choked up as he shares that he'd tell his mom Amy Roloff, "Mom, they ran away again."

"Then my mom would yell at Jeremy like, 'Don't leave your brother behind.' It was so demoralizing because it was such a little brother thing," he says. "I'm not the little brother, so."

"That collision of confidence and self-worth and then reality is what hurts the most," he continues, sadly noting, "It's coming for him. It's coming for all my kids."

Little People, Big World airs on Tuesday at 9:00 ET/ 8:00 CT on TLC.