2 Series, 9 Episodes
Sheldon and Amy attempt to celebrate her birthday with an intimate night at home. Bernadette goes into labour, so Howard, Raj and Stuart rush the expectant mother to the hospital.
Sheldon, Amy, Leonard and Penny divide up all their possessions into two separate households, but tension ensues. Raj and Stuart compete to become indispensable to Howard and Bernadette.
Sheldon can't contain his jealousy when he hears that his university colleague Bert the geologist has won a prestigious fellowship. Howard finds an old remote-controlled toy that he made in the past.
Sheldon goes to great lengths to convince Amy that they should have a baby together. Raj feels too embarrassed to tell his friends what the new woman in his life does for a living.
Amy lies to Sheldon by telling him the completed repair work on her flat is still ongoing so that they can carry on living together. Penny moves Leonard's collectables into storage behind his back.
Penny and Leonard attend a comic book convention, where Penny is surprised to meet fans of her acting work. Sheldon and Amy host a brunch at Penny's flat and Howard makes an impulsive purchase.
Leonard and Penny intervene when a cohabiting Sheldon and Amy have an argument about their 'bathroom schedule'. Howard and Bernadette's secret stay-cation is interrupted by unexpected guests.
When Amy's apartment is flooded, she proposes a 'cohabitation experiment' with Sheldon while it is repaired. Raj finds out the gender of Howard and Bernadette's unborn child before they do.
The guys work around the clock on the Air Force project, leaving Sheldon fighting to stay awake. Penny and Amy attend a university gathering. Raj learns Bernadette's true feelings about her pregnancy.
Howard has a meeting with Air Force representative Colonel Williams about the gyroscope he invented with Leonard and Sheldon. Penny carelessly reveals Bernadette is pregnant to her colleagues at work.
The group of friends face an awkward morning after Sheldon's mother and Leonard's father share an evening together. Penny's family arrive in town to attend Penny and Leonard's second wedding ceremony.