Leona LewisWhy is Leona Lewis so giddy?

Maybe it was the thought of all of those scantily clad Agent Provocateur babes...

Or, maybe the sight of a glass of champagne or two?

In any case, this is a rather less demure side to the star than we've seen before.

The singer went out on the town with the Sugababes for the AP party, and revelled in some girly fun.

Leona even stuck to the lingerie company's sexy theme, swathed in an LBD, and a pair of sky-high boots.

It's about time the singer veered away from the ol' straight and narrow approach, usually accessorised with prom dresses and coy looks.

And, we must say... we like it.

After what could have been a knees-up at the Sanderson hotel, Leona arrived at the Koko club with Keisha Buchanan to join in the naughtiness of the AP party.

While getting out of the car to enter the Camden club, it looked like Leona was enjoying a fit of giggles.

Throw off those goody-two-shoes shackles more often, Leona, it's good to let go once in a while.