N-Dubz bandmate Cheryl Cole as a judge on The X Factor, Contostavlos has become a huge star in her own right, with the source explaining: "Tulisa wants to make sure that they handle it professionally and continue not to talk about their relationship."
"She told him not to hint that she's his girlfriend any more" with the insider adding that X Factor bosses have given the pair tips on how to handle the new found interest in their love lives.
They explained: "It's tough to know what to say and do. The judges' relationships have to play second fiddle. Their personal lives can't overtake their work on the show."
Tulisa also recently branded her 'mystery' boyfriend "her rock" on Twitter, but the 23-year old still refused to name him after being bombarded with tweets suggesting she was talking about Fazer.

[uuid=de6c6bc2-37a7-4e34-a260-5cffb97d24ef]SEE PICS OF TULISA FROM THE X FACTOR 2011 HERE![/uuid]

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