See adorable pictures of Kate Middleton carrying her 6-month-old son, Prince George, while arriving on vacation in Mustique on Jan. 25. Credit:

Royal cutie! Kate Middleton was photographed arriving on her first overseas vacation with son Prince George on the West Indies island of Mustique on Jan. 25. The new mom carried the 6-month-old heir to the British throne in front of her while deplaning. See more pics here.

Baby George looks even more adorable since his July 22 birth and last public appearance at his Oct. 23 christening. The beautiful baby boy wore a white long-sleeve onesie, and matching sun hat.

Middleton, still looking fit and slim post-baby, dressed in casual attire for the flight. She wore a long-sleeve white and navy striped Ralph Lauren shirt, J brand skinny jeans and Mint Velvet shoes. Middleton, looking like she has a handle on motherhood, expertly juggled George while smiling at photographers.

The vacation marks Prince George's first passport stamp since his July 22 birth. The Duchess jetted off to Mustique for a weeklong getaway feting mom Carole Middleton's 59th birthday. Dad Michael Middleton, brother James, and sister Pippa were also in attendance for the celebration. Middleton were accompanied by protection officers while flying first class on British Airways with George and James. The group stayed at the approximately $18,000-a-week Rocina villa, where they have stayed before.

Although husband Prince William stayed behind for University of Cambridge classes -- where he is studying agricultural management, Middleton didn't need a nanny. (The couple have been using trusted nanny Jessie Webb on a part-time basis. She cared for young Princes William and Harry.) 

A source tells Us Weekly, "George was good as gold on the plane."