The man behind hit series Glee was blocked from entering his own TV set by Britney Spears' body guards.
Ryan Murphy - who wrote and produced the musical show - admits security was so tight whilst the pop star filmed cameo scenes, that at one point he had to stay outside the studio.
Murphy said: "It was literally like the president came. We all had to wear wristbands. I couldn't get into my own set at one point which I thought was hilarious. Literally, it was like, 'Who are you?' But, you know, we just wanted to protect her and make it great."
Despite the extra measures, Ryan praised the Hit Me Baby singer for her "sweet and humble" attitude to the young performers who starred alongside her.
"We had a number with a bunch of eight-year-old dancers in the show and she spent a lot of time talking to them and they did a number for her and she was so sweet. She's great with kids, she was awesome."
Britney takes on the role of Madonna for her guest appearance and does a rendition of their 2003 music video Me Against The Music.