The superstar couple donned all black for the family affair in Los Angeles, paying their respects to the 17-month-old, who died in his sleep a week ago after showing no previous signs of illness.
Kardashian, 36, wore an ankle-length black dress, a fur overcoat, and a pair of oversize black sunglasses for the event, and wore her long black hair loose down her back. West, 39, wore an all-black suit and large amber shades for the funeral.
Anderson is West’s cousin on his late mother Donda’s side of the family, and he currently works with the “Fade” singer at his label, G.O.O.D. Music, in Los Angeles.
The devastated father posted a black-and-white photo of the little boy to his Instagram account on Monday, March 13, with a heartbreaking message: “Today was the worst day of my life!! I lost my lil man and gained an angel! Rest in Paradise!!!! I love you man.”
In the days since, he has shared a number of cute clips of Avery playing with a bulldog, giggling in bed and brushing his teeth.
Want stories like these delivered straight to your inbox? Sign up now for the Us Weekly newsletter!