But it wasn't sadomasochism, it was death! Despite the song being about how she says she doesn't need him and insults him and then he decides to leave and she says "wait, don't go, I really do need you, I just can't admit it!" , the video is about her obsessively needing him in an overwhelmingly clingy way, leading to her eventually wanting to kill him and
stuff him, so that he'll never leave, but stay forever, and she'll keep him in her closet with all the other people and animals who tried to leave her at one point, preserved for all of time. Except the problem is she becomes so terribly lonely then, because they don't move and even though she can admire them and they aren't trying to leave anymore, they won't interact with her. So then she goes out and seeks a new special companion, and wins him over, but he starts wanting to leave her just like the last one did, and it starts all over again. She's a serial killer after all.
Anyway, the sort of person who would treat people they care about like shit and then realize they really need them and they're sorry when that person decides to walk out... is not the sort of person who would be a clingly obsessive serial killer... So then really the video is about the intensity of her pushing away someone she cares about and then pulling them back... As though torn between the sort of "fuck you, go away, you don't mean anything to me, I don't need you, leave" feeling and the "oh no, I desperately need you, I'll kill you before I let you leave, please don't go, stay with me forever" feeling. And the video is kind of stretching it out to absurd levels, making fun of it. This of course shows just how obnoxious she feels she really is, or perhaps how difficult she is, in relationships.