Penny has had many great moments in The Big Bang Theory proving that she is a decent person at heart. But there have also been times when Penny's darker side has taken over. On some occasions, Penny has done some outright horrible things or retold stories of her high school days where, by Amy's own words, she was a bully.
There are certain things that Penny has done that fans can't let go of, but there are some that are just outright shocking such as leaving a girl blindfolded in a field, or verbally abusing someone with anxiety. Granted, she does look out for her friends at times, but not always.
Used The Gang's Wifi & Food
It's commonly known that Penny was a struggling actress in the first few seasons of The Big Bang Theory, therefore she took any and every opportunity to use her friends' food and wifi without paying. It was clear that Leonard was okay with it but Sheldon was against it.
There was even one occasion after Leonard and Penny broke up when she said "Oh you wanted me to pay?", showing that she never even considered paying for her own food. Surely if Sheldon wasn't okay with her using their things without paying, the normal thing to do would be to stop.
Made Leonard & Sheldon Get Her TV From Kurt
Way back in season one Penny uses the shower in Leonard and Sheldon's apartment, and one of the first things she asks of them is to go to her ex-boyfriend Kurt's house to retrieve her TV.
Penny knew that Kurt was not a nice guy, and built like a truck, therefore, asking Leonard and Sheldon to go and essentially confront him was a horrible move.
Put A Girl's Retainer In The Toilet & Forced Her To Use It again
Penny has recounted her bullying past a number of times. In season 5 episode 11, 'The Speckerma Recurrence', Penny told Amy and Bernadette a story.
Apparently back in high school, Penny and her friends put a girl's retainer in the toilet and then forced it back into her mouth. Sure this was a laugh on the show but this was a horrible act, so much so that it led to Amy fully calling Penny a bully.
Got In Bed With Raj
Fans will always remember the moment in season 5 when Penny and Raj woke up in the same bed together. To be honest, out of the rest of the gang, Raj is probably the second most likely to date Penny as Howard and Sheldon's chances are essentially zero.
Still, fans didn't hear the full story and even though they didn't have sex, this is definitely not a decision that Penny would have made sober. What's even more shocking is that Raj made her think they did sleep together.
Didn't Tell Leonard About Not Wanting To Have Kids
The show made it to season 12, and through the many ups and downs of Penny and Leonard's relationship, the two eventually get married and begin to live their lives together. However, even though their relationship began many years before, Penny decided to wait until years down the line to tell Leonard that she didn't want kids.
This could have been a major issue for the relationship if kids were something Leonard really wanted. What if Leonard, after years and years of pursuing Penny, engaging in a relationship, and getting married were to find out that she didn't want a family?
Trash Talked Bernadette In The Office
After her job at The Cheesecake Factory and her struggling career as an actress, Penny was lucky to have a friend like Bernadette who managed to get her a job as a pharmaceutical sales rep.
In return, Penny decided to trash talk Bernadette to her boss when she found out he was scared of Bernadette in season 8. She also outed Bernadette's pregnancy to the office before she was ready.
Called The Gang Pathetic
In season 1 episode 14, 'The Nerdvana Annihilation', the gang invested in a full-sized prop time machine from the movie The Time Machine. As the gang tried to get it up the stairs, they start to really struggle which makes Penny late for work as she has to go up to the roof and jump across to the adjacent building.
Penny proceeds to shout at the whole gang and call them "completely pathetic" and tell them that they waste their money. Fans will understand that she is angry but calling them pathetic to the point of Leonard wanting to sell all his collectibles was very harsh.
Grilled Lucy
In season 6, Raj makes a speech about the family of people who attend the comic book store, and a girl Lucy comes up afterward to compliment his speech. The two end up dating and Lucy breaks up with him in an e-mail.
When Penny goes over to check her out, she ends up calling her a bad person. Saying this to someone with anxiety certainly wasn't right. This could easily have ended badly for Lucy, potentially scarring her for life.
Left A Classmate Blindfolded & Stranded In A Field
One other of Penny's bullying tales she told Amy and Bernadette was that she and her friends blindfolded a girl, tied her up in a field, and left her stranded overnight. Yet again Penny has shown that she was a horrible person in high school.
Granted, she has grown a lot since then and is probably not this way anymore, but with each story, fans certainly get more and more shocked at Penny's past actions.
Told Howard He Was Going To Die Alone
In season 2 episode 12, 'The Killer Robot Instability', Penny and Howard have an argument after Howard states that he and Penny have started their usual flirting. The argument escalates and Penny takes it a step too far by saying that no girl would ever want to flirt with Howard and that he will grow old and die alone.
This is by far the harshest thing that Penny has ever said to any one of the gang and comes as a surprise from someone who has been hurt in relationships before.