After his family sang happy birthday, Rex eagerly jumped up to take a closer look at the towering, sparkler topped cake and spotted the heartbreakingly sweet and very artistic tribute to the family's pet dogs on the cake in the form of detailed fondant models.
WATCH: Stacey Solomon's heartbreaking birthday cake tribute
In the video posted on Instagram, Rex saw the models of dogs Teddy, Peanut, and Theo wearing party hats and exclaimed: "Look! That's Peanut, has he got a birthday hat?!" After a moment of suspense and a nervous giggle from mum, Rex continued in awe: "...and Theo! Yay!" Stacey was delighted. Theo was the much-loved family pup who sadly passed away last December.
Cake toppers modelled on dogs Theo, Peanut and Teddy
"Rex is in love with them, he was so happy to see Theo on his birthday," Stacey captioned the post with a teary-eyed emoji. The thoughtful gesture was so adorable that nearly two hundred thousand fans and celebrities alike wished Rex a happy birthday in their droves.
Fellow DIY queen and best friend Mrs Hinch was one of the first of Stacey's celebrity pals to comment, writing; "Amazing. Rex's little face Stace. Happy 3rd birthday beautiful boy. I just know you would have had the bestest day ever. Lots of love from me, Jamie, your bestie Ronnie and Lennie. We love you xxx"
See the towering birthday cake
The dog cake toppers were made by a small business named 'Cake Topper Animals' that specialises in creating lifelike mini models of pets from photographs. The rest of the huge cake was finished with sparklers and was hand-painted with forest decorations and shiny gold. The amazement on Rex's face proved that it was a job very well done.
Epic dino-themed garden party
After a wonderful day spent running around the family garden, which had undergone an impressive makeover to suit the party's dinosaur theme, Stacey told fans: "Thank you for all of your lovely messages! He's had the best most simple day & now fast asleep and we aren't far behind him."
Stacey shared a video of Theo riding a dinasour
Last year, Stacey threw Rex a Disney's Moana themed birthday party and the family all dressed up in their Essex home surrounded by balloons and Hawaiian themed decorations. It was even more impressive when Stacey's post revealed that much of it was her own handiwork.
Rex enjoyed a Disney Moana themed party last year
She wrote: "Mummy will keep working on her costume skills as you grow, I promise." It's fair to say that DIY queen Stacey has outdone herself in the best possible way.