PHOTOS: Alia Bhatt, Sidharth Malhotra and Kriti Sanon attend Karan Johar's birthday bash

Alia Bhatt and alleged boyfriend Sidharth Malhotra headed towards the residence of their mentor Karan Johar in Mumbai today. The filmmaker just turned 45 and the who's who of B-town was there to wish him on his big day. His proteges Alia and Sidharth, who debuted in his movie Student of the Year, were only too happy to shower wishes on KJO.

Alia took to Instagram to share an emotional post on the occasion of KJO's birthday. She wrote, "Happy Birthday to my most favourite person in the whole world! @karanjohar you're my friend, my father, my teacher and last but not the least you're my in house fashion police ( the only one that matters ) hahah I don't know what I'd do without you!!! Love you karan."

Alia was last seen in KJO's Badrinath Ki Dulhania opposite Varun Dhawan. The movie was a hit at the box office. She is currently busy prepping for Ayan Mukerji's Dragon opposite Ranbir Kapoor.

Sidharth on the other hand will next be seen in Reload opposite Jacqueline Fernandez. Sidharth will also be seen as an army espionage agent in Neeraj Pandey's upcoming directorial Aiyaary. The project also stars Manoj Bajpayee and is based on true events. It will be a 2018 Republic Day release. It revolves around the relationship between a mentor and a protégé. "I am really thrilled to work with Neeraj as he always brings an element of reality to his content. It is going to be very interesting, looking forward to start shooting," Sidharth had said in a statement. 

Also seen heading towards KJO's bash is the lovely Kriti Sanon. She will soon be seen in Raabta opposite Sushant Singh Rajput.