Filming proceeds smoothly – makeup artists do touch-ups, a prop master replenishes the pickle supply – with humor and camaraderie between takes. When a reshoot is needed because Simon Helberg, who plays Howard, held his napkin in the wrong hand, Kaley Cuoco, who plays Penny, lifts her food box high and mockingly asks, “Does it go over my head? I don’t remember.”
Two nerdy physicists share an apartment and an unlikely friendship with their beautiful neighbor with whom one of them is infatuated. Like the universe after the big bang, the show's popularity expanded, thanks to breakout star Jim Parsons, along with the chemistry among the friends and the developing romance between Leonard and Penny. The addition of Melissa Rauch and Mayim Bialik in later seasons also enhanced the stories and relationships of the leads.
And while the actor, 44, doesn't have any other gigs lined up just yet—his most recent stab at producing, CBS' Living Biblically, was canceled after 13 episodes in 2018—he's busy preparing for his biggest role yet: fatherhood. On May 3, 2019, he and girlfriend Alaina Meyer announced that they were expecting their first child together. "We are absolutely over the moon to announce that we will soon be welcoming a little one into this crazy and wonderful world," he wrote on social media, sharing the big news. "There truly is love out there for all. We hope ours is the ember of yours, as we feel yours is the ember of ours."
One of the recurring plot lines is the relationship between Leonard and Penny. Leonard becomes attracted to Penny in the pilot episode and his need to do favors for her is a frequent point of humor in the first season. Meanwhile, Penny dates a series of muscular, attractive, unintelligent, and insensitive jocks. Their first long-term relationship begins when Leonard returns from a three-month expedition to the North Pole in the season 3 premiere. However, when Leonard tells Penny that he loves her, she realizes she cannot say it back. Both Leonard and Penny go on to date other people; most notably with Leonard dating Raj's sister Priya for much of season 4. This relationship is jeopardized when Leonard comes to falsely believe that Raj has slept with Penny, and ultimately ends when Priya sleeps with a former boyfriend in "The Good Guy Fluctuation".
When Leonard receives a braggy Christmas letter from his brother, he feels bad about how little he and Penny have achieved in the past year. Leonard wonders if he and Penny should be thinking about the next step after two years of marriage, like buying a house or having a baby. Penny tells him she wants to do all those things someday, but she has a bunch of stuff she would like to do first.