Lady Gaga treated Beyonce to a cracking surprise on her birthday - by presenting her Telephone collaborator with a diamond-studded whip.

The R&B superstar turned 29 on Saturday and her pal Gaga ensured her day was a naughty one by ordering the custom-made leather toy and a matching lingerie set. Gaga also treated Beyonce to an a capella rendition of Happy Birthday backstage at Jay-Z's concert with Eminem in Detroit, Michigan last week .

A source tells Britain's The Sun, "Gaga wanted to give her something special. The whip was made out of hundreds of diamonds and leather. When Beyonce received it she squealed with excitement. The dressing room was decorated with balloons and banners and a lot of champagne had been put on too."

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