So, I'm new to mating cats. I have a 2 year old female cat who's going through heat for about 5 days already. She shows the signs; she's very loud and affectionate (she's very aloof when she's normal :\), she rubs herself on the floor, raises her butt in the air and things like that but she doesn't let my male, who's been with her for a year already, mate with her. She fights with him whenever he tries. I've tried introducing her to other tomcats in the past but she just wouldn't let them. Is this normal or just some weird mating ritual?