Jessica and Ashlee Simpson’s little ones Bronx and Maxwell look adorable as they pose in front of the family Christmas tree

They’re four years apart in age, but have always been the closest of friends.

And so it’s no surprise to see Ashlee and Jessica Simpson’s eldest children, Bronx Wentz, nine, and Maxwell Drew Johnson, five, are quickly becoming best buds.

Jessica, 37, took to Instagram on Wednesday to post an adorable snap of the two little ones posing in front of the singer’s Christmas tree in Los Angeles.