While their fans wanted Ranbir Kapoor and Katrina Kaif to celebrate Valentine's Day together, the actors did just the opposite. If Katrina was busy filming 'Bang Bang' in Shimla, the Kapoor lad, as reports suggest, partied till the wee hours with his friends including Aditya Roy Kapur at a nightclub in Mumbai. If rumours doing the rounds are anything to go by, Ranbir and Katrina had a tiff during their recent US trip
