Taking to Instagram Stories, Alia shared a picture with KJo from her wedding day, and wrote: "Happy birthday to the most loving, generous and pure soul....my K! No words are ever enough to tell you how much I love you!"
Varun shared a picture with Karan and the latter's son, Yash.
The actor captioned the post: "Karannnnnn ur the funniest most intelligent human being I know with the largest heart...love you always no conditions apply."
Sidharth posted a photo with KJo from his chat show 'Koffee With Karan' and said: "Happy birthday... wishing you a year filled with love and excellent health. Big hug!"
Karan launched the trio -- Alia, Varun, and Sidharth -- with his 2012 romantic comedy directorial 'Student of the Year'.
