“They both feel Khloé has gone through so much and that she deserves being happy,” the source tells PEOPLE. “They can’t believe that Tristan has been going behind everyone’s back. They find his behaviour disgusting.”
When Kanye returned to Twitter this week, the star seemed to shade Tristan by shouting out his former brother-in-law and Khloé's ex, Lamar Odom.
"My favorite moment of walking into MSG to play Saint Pablo, I used to go to the hospital and play Lamar the album when he was learning to walk and talk again Then we walked into the arena together," he wrote.
Khloé, 33, and Tristan, 27 welcomed their first child together, a daughter named True Thompson, just days after footage of the NBA player allegedly cheating on the reality star came to light.