"Santa and his little helpers," posted proud mum Giovanna alongside the picture of Buzz seated in-between stuffed toys of Mickey and Minnie Mouse. "Can't believe Buzz is 9 months old today!! Xxx."
Giovanna's McBusted star husband Tom echoed his wife's disbelief that the time had flown by so quickly.
"Well, well, well, our little fella Buzz is 9 months old today," he tweeted. "That has gone unbelievably fast!!!"
On Friday Tom posted a photo of his son examining a Christmas tree decoration, clearly enthralled by the adorned tree and its twinkling lights.
Tom and Giovanna, who tied the knot in May 2012 after first meeting at the age of 13, are no doubt looking forward to spending their first Christmas as parents.
On 25 December 2013, author Giovanna was six-months pregnant with Buzz, who was welcomed into the world on 13 March 2014.
In her latest post, HELLO! Online blogger Giovanna revealed that Buzz's first teeth recently appeared.
"I thought Buzz was going to be rocking the gummy look well into his teens," she wrote. "But his first tooth arrived and it had company… his second tooth! Yep, two bottom teeth have appeared from nowhere, much to our surprise and his indifference.
"He already loves his food, and I imagine he’s going to love it even more now that he has teeth to tackle it with."