This might as well be a scene straight out of Karan Johar's film, 'Student of the Year'. At the filmmaker's party, his star students Varun Dhawan and Sidharth Malhotra apparently had a falling out. Says a source, `Varun and Siddharth were present at Karan Johar's birthday bash and there was a heated debate between the two of them.`

The source adds that it all started with a joke, but soon things got out of hand and it turned into a heated argument. `Sidharth took offence to Varun's comment and the two had a fight. Some people at the party then had to interfere and sort things out. Soon after, Varun left the party,` says the source.

However, Sidharth denied the story. `Nothing really happened between Varun and me. I don't know where all these rumours come from,` he said.

Varun remained unavailable for comment.