Kim was referring to her earlier appearance on The Ellen DeGeneres Show, in which she described Tristan's actions as "so f***ed up".
Last month, video emerged showing Tristan allegedly kissing a strip club bartender on a night out in New York.
Footage also surfaced of the NBA player getting close to two women on another occasion last year.
Soon after the story broke of Tristan's alleged infidelity, Khloe gave birth to their first child together, a daughter named True.
Multiple reports suggest Khloe has since taken Tristan back, with the reality TV star photographed supporting him at one of his basketball games and on a movie date.
According to People, Khloe's decision to stay with Tristan has caused "friction" among her family.
A source told the publication the Kardashian clan had "no desire" to celebrate Mother's Day with the sports star.
"Khloe's decision to stay with Tristan has definitely caused friction. Her family hasn't visited her for weeks. It's been hard for Khloe, but she is doing what she believes is best for her family," they said.