Kristin Cavallari isn't the cheating type -- despite what one tabloid mag wants its readers to believe.
The 24-year-old MTV reality star is discrediting a new story alleging she had an affair with Scott Disick, who has been in a committed relationship with Kourtney Kardashian since 2007.
"It's 100 percent not true," Cavallari said on The Billy Bush Show Wednesday.
The Hills star -- who's back on with Chicago Bears quarterback Jay Cutler -- added that her ex-fiance "didn't believe [the report] for one second."
Cavallari said she was also upset that Disick, 28, and the Kardashian family didn't deny the tabloid story outright.
"I just think, what convenient timing for them with their show premiering next week. With everything that's going on for Kim, I feel like they're trying to take the heat off her," she said. "When there's a big story like that, they always call you and ask if you want to comment and clearly none of them denied it."
"It's disrespectful to me and Jay," Cavallari added, "and I think it just says a lot about their character."