Howard Wolowitz (Simon Helberg) finally gets his revenge on Sheldon Cooper (Jim Parsons), without even intentionally doing it, in the latest The Big Bang Theory episode. In general, Sheldon isn't really known for treating anyone else well. He tends to look down on his colleagues, bully his friends, and even his own wife. In short, he can make hanging out with him very difficult. But he has never treated anyone worse than he has Howard.
Sheldon's bullying of Howard has gone on for years. While he already operates on the notion that he is intellectually superior to everyone else in his life, he loves doubling down on that when it comes to Howard - the only one of the boys without a PhD. While he may not have risen to the same academic level of some of his peers, in terms of actual accomplishments he's really the only one that has a solid resume, having worked at the international space station. Sure, he's earning less than Bernadette (Melissa Rauch), but at this point, he's also the sole member of the group who has a good work and life balance.
Despite all this, Sheldon likes to mock Howard every single chance he gets. The inciting incident from season 7 didn't really start intentionally. Back in season 7's 'The Thanksgiving Decoupling', Bernadette's father, Mike (Casey Sander), spent Thanksgiving with the gang at Mrs. Wolowitz's house. Having never been able to connect with each other, Howard made the conscious effort to bond with his father. Considering Howard grew up without a dad, he isn't really that knowledgeable about the usual activities and things a father and a son usually bonds over. No wonder his plans quickly went south after he struggled understanding football - something Mike is very fond of.
To make matters worse, Sheldon (who had been giving Howard a difficult time throughout the whole episode) easily connected with Mike, having grown up with a dad who's also a football coach. It was pure coincidence, but it didn't help that Sheldon and even Mike proceeded to make fun not only of Howard, but also his mom. Bernie and Amy (Mayim Bialik) eventually stepped in to chastise the drunken pair, forcing them to apologize for their inappropriate behavior.
The incident has since then been forgotten and was chalked up as just another one of Sheldon and Howard's numerous clashes. It was, however, revived in this week's episode of The Big Bang Theory, titled 'The Consummation Deviation', when it was Sheldon's turn to smooch up to his new father-in-law, Larry Fowler (Teller). Sheldon planned to butter Larry up first before trying to charmAmy's mom, Mrs. Fowler (Kathy Bates), who's much scarier. But as expected, Sheldon (who's ignorant of social cues) didn't realize the Fowler patriarch was miserable the whole time he was with him until the two stumbled upon Howard in the comic book store. There, Howard easily won Larry over with a single magic trick - obviously also a meta-joke, considering Teller's magician roots.
Throughout the whole episode, Larry continued to hound Howard to teach him of his ways, genuinely wanting to learn how he does it, to Sheldon's annoyance. Just a few episodes ago, in 'The Imitation Perturbation', Sheldon mocked Howard’s magic tricks and said that no one is ever interested in them - words that have now come back to bite him. In the end, Sheldon just opted to go to his mother-in-law in an attempt to bond with her instead. There, his plans were more fruitful as he and Mrs. Fowler quickly settled into a relaxed relationship. But with Amy now seemingly planning to spend more time with his parents moving forward, it'll be interesting to see if Sheldon and Larry will ever get to bond with each other.