PHOTOS: Britney Spears - Gleeful In Yellow String Bikini

Fresh off shooting her guest appearance for FOX's hit show Glee in Los Angeles, Britney Spears donned an itsy bitsy teenie weenie yellow string bikini in Hawaii, and RadarOnline.com has the brand new pics of the Circus singer.

Brit, 28, hit the beach looking tanned and toned with agent/boyfriend Jason Trawick.

The new season of Glee premieres September 21st; Spears' appearance will come the next week, on September 28, and while the plot line is hush-hush, Glee's creator/executive producer Ryan Murphy recently hinted that the Toxic singer shows up as cast members hallucinate under anesthesia at the dentist, played by John Stamos.