"He wants to have kids now," Kardashian told sister Kim Kardashian.
"Tristan and I definitely talk about starting a family. He wants to have five or six kids with me and that's lovely. We could start at one and we could grow from there," she added in a confessional shot. "It's scary. It's a really big step."
Kardashian and Thompson were first linked in October following their respective splits from James Harden and Jordan Craig. Craig gave birth to her and Thompson's son Prince in December. Kardashian later told ES Magazine she and Thompson want children of their own.
"I would love to have a family," the star said. "We've talked about it. He [already] is a father, and I know for a fact that he would be an impeccable father. I definitely want to be a mom. But I don't put the pressure on it."
"[I've] never been in this type of love," she gushed before confirming she would say "yes" if the NBA star proposed.
Kardashian finalized her divorce from Lamar Odom in December after initially splitting from the former NBA star in 2013. Odom's daughter, Destiny Odom, recently told People her dad's marriage to Kardashian was "toxic."