The model used a flower emoji to cover some of her breasts in the picture, as the new mum sweetly embraced her son.
In the caption, Krystal confirmed that the image had been taken just six weeks after his birth.
"Where has the time gone?!" she wrote, writing that Sunny was now almost three years old.
"YOU ARE and ALWAYS will be my Baby, No matter how big you get! May we never lose that bond."
The star regularly shares cute snaps alongside her toddler.
Forscutt shares her son with husband builder Neil Hipwell.
The model who has graced a number of male magazines rose to fame in the 2006 season of Big Brother.