<p><br /> Gleeks contain yourselves! Britney Spears has given a sneak preview of her cameo on US series Glee.<br /> </p><p><br /> The star posted an image from her first day's shoot on her Twitter page. Standing alongside her assistant, the star, 28, can be seen dressed in a waistcoat and wearing glasses.<br /> </p><p><br /> She told fans: "Having so much fun on set!! Can't wait for you guys to see the episode! -Britney."<br /> </p><p><br /> Glee creator Ryan Murphy said earlier this year that the episode dedicated to the pop princess would be called Britney / Brittany and will poke fun at choir leader Mr Schuester, who does not want the Glee club to cover the hit singer's songs.<br /> </p><p><br /> The episode is sure to be one of the highlights of series two, which returns to US screens in September.<br /> </p>
