The friendship between Amy and Penny of The Big Bang Theory is a fulfilling one. Much like Penny and Leonard’s relationship, Amy and Penny balance each other out. Their differences are what bring them together as they learn new things about the world. Amy finally gets the social circle she always wanted when she was a young girl and Penny finally has a friend who is worldly and teaches her things besides how to use a credit card. While Amy’s obsession with Penny was known early on, Penny didn’t admit Amy was her best friend until Amy and Sheldon started planning their wedding. And although the two are close as can be by the 12th season, Amy showed many signs of jealousy with Penny. Keep scrolling to see 10 green-eyed monster moments.

PENNY IS VERY CLOSE TO SHELDON

Penny has known Sheldon since season one whereas Amy didn’t meet him until the third season. And even when Amy got to know Sheldon, they didn’t become close until season five when Sheldon finally asks her to be his official girlfriend.

This means that Sheldon and Amy had a lot of time to get to know each other on a deeply personal level. Unlike Leonard, Penny was able to listen to Sheldon and give him similar advice his mother would give him (minus the biblical talk). Their trust within one another and Sheldon’s ability to open up to Penny makes Amy jealous. She even expressed this to Leonard in “The Anything Can Happen Recurrence.”

AND SEEMS TO BE CLOSER TO SHELDON’S MOM THAN AMY IS

We first met Mary Cooper in the first season, meaning she already knew Penny for at least three to four years before she ever met Amy. As Sheldon’s mother, one would assume she was also a brainiac with a lack of social awareness but she’s the complete opposite. Though she dedicates her life to God and the church, she is extremely humbling and relatable, which draws Penny to her. Mary Cooper is sort of like a mother-figure to Penny since she sees Mary more than her own mother. This, of course, can make Amy feel awkward. Not only does Penny have the ability to make Sheldon feel comfortable but she also has the social workings to draw Mary Cooper in — an ability Amy isn’t all that familiar with.

SHE’S CONSTANTLY PRAISING PENNY’S GOOD LOOKS

This fact is very apparent when Amy first joins the friend-circle. When Amy first joins the group, she notices that Penny is very bad at her job but her initial judgment of her changes after their first girls’ night. She soon starts making comments about Penny’s golden hair, her laugh sounding “musical,” and her perfect body. She wants to be apart of Penny’s world because Penny is, essentially, the “cool girl.”

Amy never got to hang out with the popular crowd in high school so this was her second chance at popularity. Some even thought Amy had a crush on Penny, especially after she kissed her at a bar and started singing “I Kissed a Girl.” However, her obsession with Penny’s looks seems to come from curiosity and wonder, not romantic feelings.

AMY IS FASCINATED BY PENNY’S ABILITY TO LIE SO WELL

When Bernadette gets pregnant for the first time, she asks everyone not to say anything. Bernadette’s job is very important to her and the last thing she wants is for her co-workers to start dismissing her because she’s a soon-to-be mother. But when Penny accidentally tells a co-worker, Bernadette becomes furious.

At first, Penny lied to Bernie and claimed she never told anyone but the truth came out when it was just Amy and Penny left in her apartment. Amy was more shocked at Penny’s ability to tell a lie than the fact that she actually let out a big secret. Her jealousy and fascination over Penny’s social abilities encourages her to do a study on Penny’s brain one day.

SHE WANTED TO BE APART OF GIRLS NIGHT

The Amy we met in season three is very different than the Penny we meet in season five through 12. In season three, she was very robotic and dry. She took things very seriously and only seemed interested in straight-to-the-point conversations. Nevertheless, when Amy realized that two women in their group were hanging out for girls night, she wanted to know what that entailed. Amy had never had a girls night before and was jealous women she knew were having one. So what did she do? She invited herself.

AMY’S JEALOUS OF PENNY AND LEONARD’S PHYSICAL RELATIONSHIP

Three years after becoming a couple, Amy and Sheldon said “I love you” for the first time. But after five years of dating and no advancement in their relationship, Amy called it quits. As we know, that breakup didn’t last long and the two finally got together and slept together by season nine but it took one too many years to get to a comfortable point in their relationship.

Meanwhile, Penny and Leonard were kissing, hugging, and sleeping together on and off in their relationship for years. Sure, Amy and Sheldon were lightyears ahead of Penny and Leonard emotionally but physically, Leonard and Penny had the relationship Amy always wanted with Sheldon.

PENNY WENT TO SEVEN PROMS

In the eighth season, the gang threw their own prom since none of them (except for Penny) had great prom experiences. As the girls were talking about their prom memories, Amy was shocked Penny went to seven proms. Or as Penny said “four ‘under the seas,’ two ’enchanted evenings,’ and one night to remember - that I can not remember for the life of me.” Considering Amy’s prom date was a mom from the janitor’s closet, Penny had the prom experience Amy literally day-dreamed about.

BERNADETTE CHOSE PENNY TO BE HER MAID OF HONOR

It was pretty comical to see how much Amy wanted to be maid-of-honor in Bernadette and Howard’s wedding. No one knew she would care so much but considering this is the closest Amy has ever been to a group of girls, she wanted to exaggerate the closeness. However, when Bernadette was going to choose Penny as her maid-of-honor instead, Amy fell into a dark depression. How come Penny always came out on top? This also made her overthink her relationship with Bernadette and wonder if they were as close as she thought they were. By the end of the episode, Bernadette realized that Amy really should get the maid-of-honor title and Penny was happy to pass it along.

MEN ONLY SEND DRINKS TO THEM IF PENNY IS THERE

In “The Hofstadter Insufficiency,” Bernadette and Amy go away for a biology conference. The two end up have an amazing time talking about science — something they can’t do too much of with Penny around.

While the two were out having a drink, two men sent them drinks to say hi and totally made their night. This was one of the first times men were sending them drinks because they were interested in them, not Penny. Amy made Bernadette realize that for once, they were the center of the attention — not their other beautiful best friend. This, of course, could come with a hint of jealousy.

RAJ NEVER HAD A CRUSH ON AMY

In another epic girls night, Raj decides to join them after he loses game night with the guys. With Penny, Bernadette, Amy, and Raj all huddled around a cocktail bar, Raj admits he always has crushes on the women his friends’ date. Amy is immediately flattered that Raj used to like her but Raj denies it. He’s blind to how rude he’s being and said he never once thought of Amy in a romantic way — just Bernie and Penny. As one can imagine, Amy was down in the dumps until they all talked it out.