I've raised my dogs since they were four weeks old so they're fine with everyone. My cat on the other hand was a rescue. I got him when he was almost 2. He's 9 now. He's perfectly fine with male guests and will let them pick him up, pet him, whatever. As soon as he hears a female voice or someone enters the house without taking their shoes off he hides and won't come back out for hours.

The running theory is he was kicked by a woman. When I got him he was covered in scratches and scabs from fighting other cats with a notch missing from his ear.