Interscope/Promotional 1 / 7
Interscope/Promotional 1 / 7

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

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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 cappella rendition of "Happy Birthday" backstage at Jay-Z's concert with Eminem in Detroit last week.

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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."

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"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."