The Worst Breach Of The Roommate Agreement On The Big Bang Theory

Living with roommates is a frequently necessary and often irksome part of life. Good communication and established, respected boundaries are the keys to peaceful cohabitation — something that the characters of the mega-hit CBS sitcom The Big Bang Theory know well. In fact, Sheldon Cooper (Jim Parsons) is so committed to getting himself and his roommate, Leonard Hofstadter (Johnny Galecki), on the same page that he creates a Roommate Agreement to which the two should adhere. This document outlines a number of rules the friends must follow while living together, and while many of them are products of Sheldon's own megalomania, Leonard goes along with it nonetheless.

Leonard and Sheldon follow the Roommate Agreement... until they don't. Given that The Big Bang Theory ran for a staggering 12 seasons, it's not surprising that more than a few of the rules were broken over the years. Some infractions were minor and easy to miss, but there was one committed by Sheldon himself that was too great to ignore. Here's the most egregious breach of the Roommate Agreement on The Big Bang Theory.

The breach of contract that had us most up in arms occurred on the season 4 episode, "The Zazzy Substitution." At this point in The Big Bang Theory's narrative, Sheldon and Amy (Mayim Bialik) have begun dating, although Sheldon is still referring to her as "not my girlfriend." Their non-relationship gets even less serious midway through the episode when the two break up after Amy (a neurobiologist) refers to physics (Sheldon's area of expertise) as a lesser science. Although he insists that the split is no big deal, it soon becomes clear that Sheldon is repressing some serious feelings about the situation.

It's obvious that things are off when Leonard comes home to find that Sheldon has adopted a cat. One cat turns into seven cats, and before anyone can stop him, Sheldon ends up with 25 felines. At this point, Leonard calls on Sheldon's mother, Mary (Laurie Metcalf), to snap him out of it. 

However, Leonard didn't need to bring in an outside arbitrator to solve this problem — he could have used Sheldon's own decree against him. The season 3 episode "The Plimpton Stimulation" references a Roommate Agreement rule that bans all pets (other than service animals) from the apartment. Sheldon was already in breach of the agreement with the first post-breakup cat he brought home; when he introduced 25 furry friends to the apartment, his rule-breaking had become egregious. And it wasn't the only time Sheldon broke this particular rule.

Way back on the first season of The Big Bang Theory, Sheldon was dealing with another tough emotional moment: the fallout from losing his job after he criticized the new head of the physics department at the California Institute of Technology. Instead of impulse-buying a few dozen cats, Sheldon turned his attention to pets of the aquatic variety.

To take his mind off getting fired, Sheldon begins experimenting with making goldfish glow in the dark. Now, this isn't quite as bad as the cats, but it's still in clear violation of the Roommate Agreement's no-pets clause. While one could argue that Sheldon's luminescent goldfish might count as service animals, as he intends to sell them as nightlights, considering they weren't glow-in-the-dark when he first brought them into the apartment, it can easily be ruled as a breach of the Roommate Agreement.

Part of what makes these breaches so bad is that they were committed by Sheldon, the creator of the Roommate Agreement. However, to be fair to Sheldon, his roomie Leonard isn't completely guilt-free when it comes to breaking the agreed-upon rules.

Leonard's worst breach of the Roommate Agreement comes on the season 3 episode "The Large Hadron Collision," when Leonard and Penny (Kaley Cuoco) are properly dating. For Valentine's Day that year, Leonard announces that he's planning a trip to Switzerland to visit the Large Hadron Collider at the CERN laboratory, the European Organization for Nuclear Research. Sheldon gets excited, assuming that he will be joining his friend... only to find out that Leonard is planning on taking Penny instead.

This is a shock to Sheldon for a number of reasons. The first is that Penny has no interest in science, and therefore isn't exactly thrilled to see the world's largest particle accelerator in action. The second reason for Sheldon's shock is that there's a very particular Roommate Agreement rule involving the CERN laboratory. Sheldon points out to Leonard a clause that clearly states if one roommate gets invited to CERN, they will take the other roommate as their guest — no girlfriends allowed.

In the end, both Sheldon and Penny get the flu and are unable to attend. Even though Leonard got off on a technicality on this one, his original intent to take Penny to CERN instead of Sheldon still counts an infraction.