"#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.
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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.