You can always try the movies first (loved them for their sheer badness. Also the actors try really really hard to make you dislike their characters, so you should mostly be safe, haha), but honestly, it wouldn't be bad if you enjoyed the books. I enjoy lots of video games that have problematic content.

Besides I think it could be fun too reading the books with the whole "abusive relationship" thing in mind, because it could give the books a whole new spin, if you know what I mean?