Rihanna celebrates her boss' 45th birthday with a cheeky throwback photo

     It was Jay Z's 45th birthday on 4^th Dec  and he likely had blowout celebration with friends and family.But besides what will ensure on his special day, the rapper got a lot of love from Rihanna on Instagram.The S&M singer took to the social media app to playfully call attention to a throwback photo of a much younger version of the rapper.The 80s-looking image features the then-aspiring artist wearing gold grills and a matching thick gold chain.With no need for a caption, Rihanna simply wrote 'Jz' alongside the upload.