Jools gave a shout out to her fourth child, who she affectionately calls 'Buds', by posting a photo of her son side-on, giving fans a closer view of his sweeping ponytail. "Happy happy birthday little buds 6 today we love you so much the kindest, sweetest quirkiest, cutest little thing and now the loveliest big brother 💙," wrote Jools.
"Arrh this makes me sad my 8 year old had long hair and wouldn't wear it up for school so they made me cut it off.... now looks like every other 8 year old.....," wrote one fan.
"The kindest, sweetest, quirkiest, cutest little thing," Jools called her son
However one follower disagreed, commenting: "Happy Birthday Buddy but Mum please get rid of the ponytail! He has fab hair just let it hang...." to which another fan responded: "It amazes me how people think it's ok to tell others how to dress/present their children."
Jamie's Instagram snap proved less controversial and showed the youngster following in his dad's culinary footsteps. Buddy was pictured flashing his biggest smile at the camera, wearing a handmade paper crown on his head as he cooked pancakes.
Buddy turned six on Thursday
"6 years old dear boy haha happy birthday little Buddy," he wrote.
Jamie and Jools have five children in total – Poppy Honey, 14, Daisy Boo, 13, Petal Blossom, seven, Buddy Bear, six, and newborn son River Rocket.
He is the "loveliest big brother" to newborn River Rocket, said Jools
The doting dad has welcomed many a celebrity into his kitchen, the most recent being Lindsay Lohan. The actress is set to appear as a special guest on Jamie And Jimmy's Friday Night Feast.
Ahead of the air date, Lindsay posted a picture of the pair at work. She thanked Jamie and his co-host Jimmy Doherty for making her feel so welcome.
Jamie has been making headlines after the odds were slashed on the restaurateur becoming the next judge on The Great British Bake Off, should Paul Hollywood and Mary Berry step down.
The popular show is set to move from the BBC to Channel 4. Presenters Sue Perkins and Mel Giedroyc have announced that they will quit after this series, although Paul and Mary have yet to comment.