Can you speak to the owner of the offending male (if you know who he belongs to) and try & persuade them to get him castrated? I have a similar problem with a nasty local male cat, who's been "done" now, but his owner left it so late that it hasn't made much difference. He's always hanging around my farm (I've got 4 female cats, all spayed and a young, neutered male) and has been known to "rape" my 2 yr old female. Her brother stood up to him the other day though (first time in his life, as he was attacked by him when he was just a tiny kitten) and actually chased him off - I was so pleased with him! Get a water pistol & squirt him every time he comes near your little lass - he'll hopefully get the message. I also find dogs are a good deterrant. Good luck!! K