"Rob's family is trying to distance themselves from Chyna. They can't stand the toxic relationship," the source continued, adding that the family naturally cares about the couple's new daughter, Dream. "It's just come to the point where they think Rob is better off without being in a relationship with Chyna."
While Jenner's big bash has become a star-studded affair in recent years -- Drake attended last year's party, as did Kim Kardashian, making her first appearance since giving birth to son Saint just a few weeks earlier -- Chyna doesn't seem too concerned by her lack of an invite.
The 28-year-old model has instead been focusing on getting her body back after baby, taking to Instagram to show off her waist trainers.
Though Rob and Chyna appear to have cooled down since their fiery blowup last week -- Rob Instagrammed an apology to Chyna on Monday, announcing that he was "seeking help," while she reposted the image with a heart emoji -- reports emerged earlier this week claiming that the pair's big fight actually turned physical.
See more on Rob and Chyna's big breakup in the video below.