The 31-year-old actor has reportedly indicated that he is in a relationship with the Tees Maar Khan star, The Times of India claims.
"He's trying too hard to get extra close to her," a source told the newspaper. "She's gullible and doesn't realise that he is portraying that they are more than friends."
The two Hindi film stars are spending increasing amounts of time together on the set of the Yash Raj production, as well as at Zafar's Mumbai residence.
"People on the set have noticed his change in attitude ever since he has gotten close to Kat. He keeps her company and entertains her in between shots. They were also spotted spending some time at his apartment," added the source.
Zafar recently donated his performance fee for Luv Ka The End to charity.
The Lahore-born actor made his debut in the Bollywood film industry in the 2010 terrorism-themed comedy Tere Bin Laden.
