Its really funny when people who's not fluent in Hindi have to fight in Hindi. Even while normal conversation its difficult for them to think of appropriate words of Hindi but during a fight its even more difficult as they are mentally not stable due to anger.
That's what happened when Upen was arguing with Praneet in washroom. I really cracked up when he said to Praneet 'Tu Shaant Rakh'. The way he said that was damn hilarious. :D