How do I stop my new kitten from using my male cat as a pacifier?

I got my kitten when she was 6 weeks old. Her mother had already stopped allowing the kittens to nurse. We noticed after the first week that she had started trying to nurse off my male cat, and he allowed it. Now she is 11 weeks old and still using him as a pacifier. His poor little are getting red and chapped. is there a way to break her of this?