We've seen a lot of low cut dresses in our time.

But we've never seen anything quite like this boob-busting number Mariah Carey wore to perform at the BET Honors awards in Washington on Saturday night.

The 43-year-old We Belong Together singer wore the sexiest LBD we've seen in a long time as she writhed around on a piano top.

The figure-hugging number clung to every inch of the singer's curvaceous body, while a deep v slit at the front left her impressive cleavage on display.