http://www.youtube.com/watch?v=qVaW3rfCwq8

When X Factor judge Tulisa Contostavlos decided to perform a sex act on her then-boyfriend MC Ultra, little did she realise it would all blow up her in face. Now she's explained the event to fans.

The former N-Dubz singer was at the centre of a sex tape storm earlier this week, after footage taken from a mobile phone appeared to show the star performing a sex act on the British urban artist. Last night Tulisa took to YouTube in order to admit that she was the woman on the clip and to provide a little context for fans.

"When you share an intimate moment with someone that you love and trust you never imagine for one minute that footage may at any point be shared with the rest of the UK," says a "betrayed" Tulisa in the YouTube clip, which we've featured above. According to the singer, her ex had threatened to release the footage online weeks ago.

"This is the person, Justin Edwards aka Ultra, who is my ex-boyfriend, that has put it online, who is the other person on the tape," the singer added, while holding a photo of herself and Ultra in happier times. The two had been an item for several years and begun dating when Tulisa was 17.

However, Ultra has since responded to the clip via Twitter and pleaded his ignorance, tweeting: "It's nothing to do with me. #backtowork." Have a look at the Tulisa's explanation above and try not to giggle when she says "I've never been the type to keep my mouth shut..."