Katy Perry celebrates her boyfriend John Mayer's 35th birthday.

At a New York bar and until the wee hours of the next morning; singer Katy Perry celebrated her boyfriend and singer John Mayer's 35th birthday.Katy's friends feared this celebration for Mayer's reputation with the ladies, according to Radar Online. However, Katy was keen at the beginning of this relationship to keep it fun but it seems that she has dangerously fallen in love with him.Just almost two years ago; Katy was married to comedian actor Russell Brand before she divorced him after a 14 month marriage in 30 December 2011.