Sharing several pictures from their private celebrations, the proud parents revealed the tiny tot was treated to a large pile of wrapped up birthday gifts whilst the room was decorated with shiny sliver, blue and white balloons.
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Alongside a snap of Robbie holding baby Beau with an "unimpressed" facial expression, Ayda joked: "@robbiewilliams face after I told him I wanted 1 more baby…"
The couple announced their fourth child's arrival on Valentine's Day after keeping the pregnancy secret – he was born via a surrogate. "Beau...We dreamed about you for years before we finally met you, exactly one year ago today," the doting mum gushed on Friday.
"From the seed of our hopes, to the smiling, gorgeous boy we are blessed enough to love today, you have been our miracle, the total completion of our family, and the best thing to come out of 2020.
Ayda shared this snap of Robbie with Beau
"Thank you for answering our call to The Universe...we love you with all our hearts combined. HAPPY FIRST BIRTHDAY BEAU Mummy, Daddy, Teddy, Charlie and Coco xxxx #happy1stbirthday #beau-tifulboy."
Ayda, 41, and Robbie, 46, are doting parents to three other children; two-year-old Coco, Charlie, six, and their eldest child Teddy, who is eight.
The tiny tot was treated to lots of balloons and gifts
The couple did not reveal to their fans that they were expecting a fourth child. At the time, Ayda said: "Spot the difference... On this Valentine's Day, we would like to celebrate love in the most awesome way... Beau Benedict Enthoven Williams."
The former X-Factor judge went on: "As with Coco, he is biologically ours, but born via our same incredible surrogate. We are so blessed to have our healthy son safely in our arms and are officially complete as a family #happyvalentinesday #surprise #familyof6 #whodathunkitinthe90s The Williams Family xx."
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