By Minnie Wright

EMILY RATAJKOWSKI put on an eye-popping display in a tiny bikini yesterday, showcasing her pert posterior for a racy Instagram snap.

The 25-year-old brunette beauty flaunted her incredible figure as she posed poolside with her friend, Barbara Knapp.

Sweeping her chocolate tresses back into a messy ponytail under a baseball cap, Emily Ratajkowski flaunted her peachy behind in a pair of tiny thong bikini bottoms, making the most of her golden tan as they soaked up the sun by the rooftop pool.

Barbara opted for a black and white patterned one-piece, showcasing he curves and flashing a hint of sideboob, also wearing her hair pulled back in a ponytail under a blue cap.

Emily shared the snap with her 12.1 million Instagram followers, wishing her BFF a happy birthday saying: "HBD, partner in crime."

Emily has been treating her fans to glimpses of her stunning curves many times over the past few days, flashing her famous derrière in a saucy swimsuit yesterday.