If the ladies have been spayed the fellas will give up after hanging around a bit, once they get the message that there's nothing doing.

In the meantime what's the problem? Visiting cats make good company. What's a bit of spraying and smelling between friends anyway? We probably smell worse to the cats than they do to us, and they put up with it. And, as folksingers, are we that entitled to complain about other creatures singing out of tune from time to time?