Pals started calling Prince George PG, so the couple took the next logical step and dubbed him Tips, the Mirror reported.
The future king has amazed his parents with his progress ever since his birth on July 22 and has already outgrown his first romper suits.
He weighed 8lb and 6oz at birth, making him the largest royal baby ever, according to a well-placed palace source.
But George is believed to have gained five pounds since then.
So at 13lb, he is already the size of an average three-month-old.
Kate is believed to be breast-feeding her first-born, topping him up around 12 times every 24 hours.
The young royals are planning to take their son to see Prince Philip at Balmoral in the next week or two.
--ANI (Posted on 01-09-2013)