Kim Kardashian, 37, is reportedly "furious" after Thompson, 27, was spotted getting cozy with a mystery woman at a Manhattan rooftop bar while a nine-month-pregnant Khloé Kardashian, 33, waits in Cleveland, Ohio to deliver her and Thompson's baby girl.
"Kim is furious over Tristan cheating on Khloé, she can't believe he would disrespect Khloé like this when she is weeks away from giving birth to his child," a source close to the Kardashians told HollywoodLife.
"Kim is livid because now is the worst possible time for Tristan to be hurting Kim's little sister whom she is very protective of. Kim knows how important it is to be calm, relaxed and stress-free in the days leading up to going into labor. This level of heartache and pain is not healthy for Khloé or her baby, which makes Kim furious. Tristan's timing could not be worse," the source added.
Thompson made headlines Tuesday night after being spotted with other women during his relationship with Kardashian. In a video published by the Daily Mail, Thompson appears to be kissing a woman; in recently-published surveillance video from October 2017, Thompson spends time with two different woman, kissing one.
Kim has reportedly turned to momager Kris Jenner, 62, to help comfort Kardashian.
"Kim is conferring with Kris and they are in full-on crisis mode," the source said. "Their top priority right now is taking care of Khloe and her baby on the way… then they will figure out what to do about Tristan."
Kardashian and Thompson started dating in 2016, four months before Thompson's ex gave birth to their son, Prince Oliver. Thompson's ex, Jordan Craig, appeared to weigh in on the scandal via Instagram Tuesday night, writing she'd "never make like of the misfortune of anyone."
In her post, Craig wrote, "If you respect yourself and you respect others, you would never make light of the misfortune of anyone, nor would you feel indemnified when it comes at the expense of others. Wishing peace for everyone."
Many fans on Twitter ruthlessly pointed out Thompson's past when Tuesday's story broke, claiming that Kardashian should have seen the infidelity coming. However, in April 2017, she gave an interview with ES Magazine, saying the fact that Thompson had a child with another woman made her more confident that he'd be a good father.
"He [already] is a father, and I know for a fact that he would be an impeccable father," she said, confirming at the time that the two of them had already discussed having children.
Kardashian has been waiting in Cleveland to give birth any day now. Many fans have speculated that she is already in labor, or else will be very soon.