When asked if such things happen in real life, Karan replied: "Today, we are making a revelation... Very honestly, this is a true story. It happened to Punit. He did actually lose a relationship."
The 41-year-old was speaking at the first look launch of the film Tuesday.
In "Gori Tere Pyaar Mein" promo, Imran's character follows his girlfriend, played by Kareena, to a village where she is working as a social worker.
Further revealing Punit's love story, Karan said: "He tried to pursue this girl, he crossed a few parts of the country to reach the heartland to woo the woman. She is now married and settled with children."
"This is an autobiographical film. 'Gori Tere Pyaar Mein' is Punit's love story. He never shared the details, but we know there was a girl."
"Gori Tere Pyaar Mein" hits theatres Nov 22.