It's still unclear when the couple broke up. Khloé and Tristan, who was caught in a web of cheating reports just days before Khloé gave birth last year on April 12, had already been spending most of their time apart, Tristan in Cleveland or on the road and Khloé in Los Angeles. Khloé hadn't been to Cleveland in about two months.
On Sunday night, according to reports, Jordyn and Tristan both ended up at a bar in Santa Monica. TMZ, which first reported yesterday that Khloé had broken up with Tristan because he cheated, heard from witnesses that the two were making out. An insider also told Us Weekly that the women "weren't allowed to use their phones at all" once they got back to Tristan's place.
A source told E! News that Khloe heard from a mutual friend about what was going on at the party, and several reportedly texted the Keeping Up With The Kardashians star.
"He doesn't even think him hooking up with Jordyn is 'bad' because he and Khloé were broken up in his mind," a source told Us Weekly. "He just truly doesn't care."
"Kylie is having a very difficult time," another source told the outlet. "She is devastated and emotional. She doesn't want to believe this could have happened. She wanted to give Jordyn a chance to explain herself."
WATCH: Tristan Thompson Tweets Then Deletes Reaction To Cheating Rumours.