Bikini explosion looming: Playboy model tests limits of swimwear to promote H2O

At one point, the top rapidly began to travel south, with Charlie watching as the fabric slipped dangerously over her cleavage.

The bikini undies were just as bad, with a minuscule amount of material allotted to cover her bits.

Bizarrely, this half-naked gyration was all to promote the purest of refreshments – good old water.