The London singer introduced her closing song 'Not Fair' by asking the girls in the crowd if they, like her, got annoyed when not satisfied by their lovers.
After huge cheers from the ladies in the crowd she asked the boys to "show me your fingers". She then gave advice to, "Think outside the box, yeah? Literally."
Allen attracted an enormous audience to her show, during which she outlined her plans to have a big party later in the evening.
"So it's the last night [of the 2009 festival], right?” she asked the crowd after opening with 'Everyone's At It'. "Are we going to have it? You're not too tired?"
Later she again mentioned her partying plans. "I'll be honest with you, we've been doing a two-week run of festival appearances, and after this I've got a three-day holiday," she explained.