Seriously, it's hard work. Howard is cheerful, but Bernadette seems to be having a full on meltdown. The baby's cry would be enough to do that to a new mom.
Sheldon: I'll have a diet Coke. Penny: Can you please order a cocktail? I need to practice mixing drinks. Sheldon: Fine... I'll have a virgin Cuba Libre. Penny: That's... rum and Coke without the rum. Sheldon: Yes, and would you make it diet?