Coleen, 27, uploaded the adorable picture to Twitter and it shows three-year-old Kai with his arm around the sleeping newborn.
Baby Klay, who was born on 21 May, looks right at home as he peacefully snoozes into his sibling's shoulder.
Kai, meanwhile, appears to have already adopted a protective streak towards his tiny brother and is gentling holding him close in the photo.
Alongside the snap, Coleen commented: "Kai loves his baby brother!!"
Coleen and husband Wayne have adjusted well to having two little boys around the house, and they even found time last week to visit a Rihanna concert to celebrate their wedding anniversary.