Kristin Cavallari Denies Scott Disick Hookup, Says She is in 'Committed Relationship'

Kristin Cavallari denied ever having a fling with Kourtney Kardashian's boyfriend, Scott Disick.

A source told Life & Style magazine that Cavallari and Disick got busy in 2009 when he and the eldest Kardashian sister were on a break.

Scott and Kourtney argued about Kristin, the source told Life & Style.

Cavallari denied ever hooking up with Disick and actually found the idea gross, according to a source who spoke with E!

It's 100 percent not true, Cavallari told Access Hollywood. And I just think what convenient timing for them with their show premiering next week and with everything that's going on with Kim I feel like they're trying to take some of the heat off of her.

She added that the rumor is disrespectful to her and to her relationship with Chicago Bears quarterback Jay Cutler. The two broke off their engagement in July but are reportedly back together.

This says a lot about their character, I think, she told Access Hollywood, referring to the Kardashian clan.

Disick -- who has a son with Kourtney Kardashian -- has not been seen at tapings of Dancing With the Stars to cheer on Rob Kardashian, who will compete in the finals.

Kourtney can't stand her now and didn't want Scott at show tapings, a source told Life & Style.

Cavallari was kicked out in the third round but she will dance in the finale with former partner Mark Ballas.

I'm excited to get back into rehearsals tomorrow for DWTS, she tweeted on Nov. 15, adding that she and Ballas were learning a new dance for it.

Cavallari has another big event before the finale: a Marine ball Thursday night. She tweeted recently about getting fitted for her dress.

But something might have been weighing on her mind Thursday morning: Glad u guys know what's up and don't believe bs! Love u guys.