You can set boundaries all you want, some people will still stomp all over said boundaries anyways - either because they do not care, or because they cannot hel

You can set boundaries all you want, some people will still stomp all over said boundaries anyways - either because they do not care, or because they cannot help themselves, or think they're in the right for doing so - and those people are often well versed in doing so without running afoul of the law, HR, or your coworkers. Being merely persistently unpleasant to be around is not a crime. Especially when setting boundaries with those who hold power over you, often the most leverage you have is a BATNA and the ability to leave for greener pastures, and the willingness to exercise said ability should they choose to call your "bluff". I won't say leaving will necessairly be your first tool, but it'll certainly be an important one, and one that might be worth using well before things get to criminally extreme cases.