Francis has cat ears and tail due to an old magic backfire via Arthur. He and his partner (does not have to be Arthur) keep them a secret from the world, as Francis has accepted them as a part of his being.

One day Francis's partner buys Francis a collar and leash for some kinky sex. Either Francis could be all for the idea, or he could be hesitant about his ears and tail being exploited like such.

Bonus: oral, and the reference to 'milk' needing to be lapped up