"#HappyBirthdayKaranJohar @karanjohar hope you have the most amazing year big hug. Wanna dedicate this song to U http://bit.ly/HBDzmc," Varun tweeted on Monday.
"EXCLUSIVE for @karanjohar on his birthday the happybirthday song from #abcd2 @ShraddhaKapoor @ABCD2Disney http://bit.ly/HBDzmc #HappyBirthday @utvfilms @ShraddhaKapoor @SachinJigarLive. Tried the rap http://bit.ly/HBDzmc," he added.
The actor has tried to rap in the peppy song, which has been shot in a colourful fashion. But Varun has no intention of joining the bandwagon of actors trying their hand at singing regularly.
At an event last week, the 'Main Tera Hero' actor was asked if he would ever be seen as a full-time rapper or singer.
To that, the 28-year-old said: "No, nothing like that. I think rapping is a way of expression. I have worked with Sachin-Jigar during 'Humpty Sharma Ki Dulhania' also and this rap (in 'ABCD 2') has been written beautifully by D Soldierz."
'ABCD 2', directed by Remo D'Souza is sequel to 2013 hit 'ABCD - AnyBody Can Dance' and it features choreographer-director Prabhudheva and international dancer Lauren Gottlieb, who were also part of the prequel.
It is slated to release on June 19.