Lucy Watson flaunts her perky posterior in sizzling throwback snap.

She enjoyed a sun-soaked trip to Tulum, Mexico earlier in this year with her beau James Dunmore.

And in the midst of all her festive planning, Lucy Watson began to reminisce about her incredible holiday as she shared a bikini-clad throwback on her Instagram feed on Sunday.

The 26-year-old former Made in Chelsea star showcased her enviable abs and narrow waist in her red two-piece as she posed on a sun lounger infront of a breath-taking backdrop of the Caribbean sea.

Aside from showcasing her cleavage in her tiny triangle silhouette top, she flaunted her pert derriere and slender pins in her skimpy Brazilian-shaped bottoms at the Sanará resort.

The E4 star complemented her beach attire with a pair of oversized shades and left her glossy brown locks loose in a straight style which cascaded down her back.

Feeling nostalgic, Lucy playfully joked that she was saying goodbye to her sensational figure for the festive season.

She wrote alongside the photo: 'Should probably say goodbye to this bod before I get knee deep in Xmas festivities