my cats, sam and noah, were like this (maybe worse) for years! sam doesn't like to play, but noah would basically torment her because he wanted to play. he just didn't understand that he was attacking her, not playing. but now, noah's simply grown out of wanting to play all the time. if it's really a problem, you could play with him more that way he's not as anxious to play with her so much. or try to find a toy he really likes.