Just like everyone else is sayin..once a tom is with a hen it is hard to call him off of her but it can be done, because i've done it before. And again,just like they was sayin, try imitating the hen or be more aggressive. If you be more aggressive it will intrest the hen and she will more than likely come to see who is tryin to take over. In other words, she wontlike the idea of some other hen tryin to take over her territory and she might come to drive you off. When she does come that tom might just come right along with her. Dont worry if she doesnt come because that tom might come to the more dominant hen(you)alone.