Siddharth (Farhan Akhtar) and Trisha (Vidya Balan) are a happily married couple until Trisha gets pregnant and things start getting complicated. Sid is not ready for a baby as he is just a struggling music composer, yet lies to Trisha. On his friends' advice, Sid starts reading pregnancy books and following Trisha's daily routine by putting a balloon in his shirt. Finally, Trisha gives birth to a baby girl and starts devoting all her time to the baby. Trisha's mother (Rati Agnihotri) feels that Sid is a careless person and can not take this responsibility, at which Sid makes a desperate attempt to behave like a family man but fails, as on one occasion he takes his baby for a walk but forgets her in the market. Frustrated, Sid ask for help from Trisha's brother-in-law Ranveer (Ram Kapoor), who is a typical family man. Ranveer reveals to him that when he gets frustrated, he makes a business trip excuse and stays in a hotel room to enjoy his life as a bachelor. Sid takes on his idea and starts staying in a hotel, with the excuse of working overnight in studio. But soon he has to cut down his idea, due to an added expense at home as Trisha decides to hire an expensive governess (Ila Arun). Sid, then, without telling Trisha, goes for a cheaper solution by shifting to a shared PG along with Manav (Vir Das), a dope-head bachelor. Sid takes Manav's advice and starts living a carefree life.