Cat domination problem

[purr]

Yes.. I got a domination problem here :)

Prince - my neutered Sphynx is my 3rd acquired cat. My middle cat is my spayed Osiris, and my oldest is Stinky. There has been some fighting between Stink and Prince as of late and I've just about had enough of it. I dont know if hes trying to become the dominant cat since hes the only male in the house. He'll back her up into the corner and then the fight starts. Hes been trying it with Osiris but she just whacks him into place but hes not backing down from Stink as he does to Osiris.

I got Feliway and it doesnt seem to do much for them - I sprayed it on the chair they scratch and the next day they're back scratching.

Any ideas?