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 Trishas 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..