I have a big black and white male cat "Ben" (14) and a female yellow Labrador "Sophie" (2).

When I first got Sophie, Ben didn't speak to us for a whole week as he didn't like the idea of a new dog as he thought he would have the house to himself after I lost my other dog.
Sophie loves to torment me with her ball as if she was going to give it to you then she backs off as if she is laughing and saying come and get it.

She always wants the last hit as when we play she loves to knock me with her nose and I trap her back and she will keep doing this till I give up.

Could someone tell me why she goes that?
I've tryed to ignore her but she just does it more and more.