Acting is a difficult thing. You have to get on screen and pretend to be someone you’re not for hours on end. Add in other people who are doing the same thing, and relationships with your co-workers can begin to get complicated. After a while, it gets difficult to separate your character’s feelings from your own. Throw in different acting styles, salary negotiations far, far beyond what most people can comprehend, and attempted romances, and you’ll likely get some bruises along the way. Here’s a few of the biggest co-star feuds Hollywood has ever seen.