chris brownAs soon as word got out that Rihanna and Chris Brown were really back together -- or at the very least publicly hooking up -- the same question went through everyone's mind: what the hell is she thinking? Yes, Chris Brown is talented. He can sing, he can dance. But can he be a good boyfriend? I think we all know the answer to that. If you are on the fence, just ask model Karrueche Tran, the girl he was dating when he and RiRi started fooling around again.

What is it about these notorious bad boys that makes them so appealing. Chris certainly isn't the only member of the scary celeb boyfriend club. So many stars treat their girlfriends like crap but still make it to the top of the hot, must-have bachelor list.

Check out 5 more of the worst celeb boyfriends of all time:

 

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