Celebrities who aren't allowed to work together

If there's one thing Hollywood is never short on, it's egos. And in an industry where collaboration is key, putting those egos in the same room (or stranding them in the desert) can sometimes produce disastrous results that range anywhere from stressful productions to full-on fisticuffs. Like combining baking soda with vinegar, here are some celebs that learned the hard way that they should probably never work together again.