Before Amy arrived, Penny already had a best friend. Bernadette Rostenkowski started as Penny’s waitress colleague at the Cheesecake Factory — the sweet microbiology student Penny set up with Howard on a blind date. Penny and Bernadette moments run from Season 3 to Season 11: double dates, girls’ nights, a rooftop wedding, a trip to Vegas, and the quiet loyalty of two women who grew up together on The Big Bang Theory.
Here are 10 Penny and Bernadette moments, in story order, that made them best friends first.
1. The Blind Date Setup — “The Creepy Candy Coating Corollary” (Season 3, Episode 5)
It all starts with Penny doing Howard a favour she does not want to do. Leonard reminds her of the girlfriend pact, and a reluctant Penny sets her Cheesecake Factory co-worker Bernadette up with Howard. The date nearly fails — until Bernadette and Howard discover they both have overbearing mothers, and sparks fly. Penny watches it happen with Leonard, delighted. She did not just find Howard a girlfriend that night. She found herself a best friend.
2. Girls’ Night, Sheldon Crashes — “The Agreement Dissection” (Season 4, Episode 21)
Penny and Bernadette are out for girls’ night when Sheldon begs to join them to escape Leonard’s girlfriend Priya — and ends up having a better time than anyone expected, waltzing with Amy while the girls drink and dance. The episode belongs to the girls, though: this is the first girls’ night where Penny and Bernadette are a unit, the two originals, with Amy still the new girl at the table. For once, even Sheldon thinks the ladies are fun.
3. Spying on Priya — “The Wildebeest Implementation” (Season 4, Episode 22)
Penny, Bernadette and Amy go to a bar to spy on Leonard’s girlfriend Priya, and Bernadette turns out to be the worst spy in television history — she cannot lie, and within minutes she has told everyone that Penny is dating an astronaut and filming a movie with Angelina Jolie. It is chaos, and it is the scene where the girls’ friendship becomes a team: Penny runs the mission, Bernadette blows it up, and they laugh about it together.
4. The Dress-Shopping Fight — “The Isolation Permutation” (Season 5, Episode 8)
Penny and Bernadette go bridesmaid-dress shopping without Amy, and Amy is furious when she finds out — she thought she was finally included. It is the first real fight in the girls’ circle, and it lands on Penny and Bernadette because they are the ones who forgot someone. The episode ends with Bernadette making Amy her maid of honour, but the lesson sticks: Penny and Bernadette learned, right here, that including people is the whole point of the friendship.
5. The High-School Bully Talk — “The Speckerman Recurrence” (Season 5, Episode 11)
When Leonard’s old high-school tormentor resurfaces, Penny has to face an uncomfortable truth: she did her fair share of tormenting back in Nebraska. Bernadette is the one who talks it through with her — no judgement, just the honesty of a friend who knows Penny’s past and likes her anyway. It is one of the few scenes where the show lets Penny be vulnerable about who she used to be, and Bernadette is the person she tells.
6. The Rooftop Wedding — “The Countdown Reflection” (Season 5, Episode 24)
Howard is about to launch into space, so the wedding moves up — and the whole gang scrambles to stage it on the apartment rooftop before he leaves. Penny stands with Bernadette on the biggest day of her life, the girl she set up on a blind date two seasons earlier now marrying the man Penny introduced her to. It is the payoff to the very first scene on this list, and one of the sweetest Penny and Bernadette moments — the moment their friendship becomes family.
7. Finding Raj a Date — “The Santa Simulation” (Season 6, Episode 11)
Raj loses at Dungeons & Dragons early and joins the girls for ladies’ night, and Penny and Bernadette take on the mission of finding him a date at the bar. It goes about as well as expected — which is to say, terribly — but the scene is a perfect picture of the two of them together: Penny confident and scheming, Bernadette sweet and ruthless in equal measure, both of them entirely on Raj’s side. Girls’ night, with a plus-one.
8. The Comic Book Night — “The Bakersfield Expedition” (Season 6, Episode 13)
While the guys drive to Bakersfield in Star Trek costumes, the girls stay home and try to understand comic books — and Penny and Bernadette’s attempt to get into the guys’ world is one of the funniest B-plots the show ever did. Collider calls this their best episode as a duo, and it is easy to see why: the two of them, alone together, funny without the guys around at all. They never needed the boys to carry a scene.
9. The Vegas Trip — “The Focus Attenuation” (Season 8, Episode 5)
The girls go to Las Vegas for the weekend, and the roles flip in the best way: Penny has to stay in and study for a field ride, while Amy and Bernadette hit the bar by themselves and turn into party animals. It is Bernadette, the sheltered one, letting loose — and Penny, the party girl, being the responsible one for once. The whole episode is a reminder of how far both of them have come since the Cheesecake Factory, and how much fun they still have together.
10. The Maid of Honour Choice — “The Matrimonial Metric” (Season 11, Episode 12)
Amy cannot choose between Penny and Bernadette as her maid of honour, and the secret experiments that follow nearly blow up the whole friendship. In the end Penny is the one who says it out loud — Amy is her best friend — and takes the role. Bernadette was in the running too, and she takes it with grace, because by Season 11 the three of them are not competing anymore. They are a trio, and this episode is the proof: the friendship Penny and Bernadette started in Season 3 now has room for everyone.
Penny and Bernadette started as two waitresses sharing a shift, and ended as two women who had seen each other through weddings, careers and babies. In Season 8, Bernadette arranged Penny’s interview for a pharmaceutical sales job — the job that finally let Penny leave waitressing behind — and by Season 12, Bernadette was Penny’s boss, and nothing between them had changed. Amy may have become Penny’s best friend in the end. But Bernadette was first, and first counts.
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