Serena Williams might have considered a bigger size of bikini bottoms if she planned to do more than sun bathing.

The tennis champ hit the waves for some surfing in Hawaii but her barely-there swimsuit pants failed to cover her behind, leaving little to the imagination.

An energetic Serena showed off a little too much of her athletic physique as she balanced on her surfboard.

Serena hit the waves with rapper boyfriend Common, while taking a break from her tennis commitments.

See the star's ill-fitting bikini below