Why? Because of some of the things he says to Pakhi that causes her to imagine things. Some may say it is Pakhi's fault. But, Raghav knows well Pakhi's infatuation for him. Still he says things to her that immediately feeds this rampant love for him.
Case in point...yesterday, when he was dancing with her, he says he's in a great mood because of the dance and the dance partner. The poor love struck girl thinks he's talking about her. Earlier, after they were coming down the stairs from the terrace, his hand "accidently' brushed against hers. Her imagination took immediate flight.
Of course, I could be way off the mark because this isn't the Raghav being portrayed. But, it could very well be a twist in the making...Like you said, things look quite ominous and foretelling. Else, he's being upfront but these things might come back to haunt his life later.