Published Sunday, 08 July 2012
The N-Dubz star was devastated in March after explicit footage, which showed her performing a sex act on ex-boyfriend Justin Edwards, hit the internet.
Contostavlos subsequently insisted the scandal had made her stronger, but she used her set at the UK capital's Wireless Festival in Hyde Park to take aim at Edwards.
She told the crowd: "Put your middle fingers up to my d******* ex, Justin f****** Edwards! Ladies, don't ever let any man pull you down, because I'm still f****** standing."
A source tells The Sun: "It was a spur of the moment decision. The crowd were totally behind her, all sticking up the middle finger to him."