At the age of 27, actor #SidharthMalhotra debuted opposite #AliaBhatt and #VarunDhawan in #KaranJohar`s #Studentoftheyear. Ever since then, he has been the `#KukkadKamaalDa` of Bollywood. Here are some fun moments of #birthdayboy Sidharth Malhotra with his co-stars while promoting his films