Kourtney Kardashian showed off her pert derriere in a thong swimsuit while on a family vacation with husband Travis Barker and their 21-month-old son Rocky Thirteen just weeks after personally putting an end to pregnancy rumors.

Kourtney certainly turned heads in skimpy swimwear as they hit the beach in Miami on Wednesday. 

She donned a black one-piece swimsuit featuring a thong while splashing around in the ocean.

Before that she covered up in a matching maxi skirt featuring a thigh-high split and lace around the hemline which she dramatically took off before going for a swim.

The eldest of the Kardashian sisters accessorized with a pair of black designer shades.

Travis looked every bit the proud papa as he carried his youngest son around for the family beach day.

After the swim in the ocean, the family continued their day of fun in the sun as they hit the pool at their luxury resort.