Beckie, I know exactly what you mean. When I met my partner I already had three of my mob and he had no pets whatsoever. Gradually, he got used to them, and even asked if we could bring Parsley to come and live with him! (She was his sisters cat who had emigrated to South Africa, and Parsley had been left with their dad - who isn't really a pet person and just left food on the porch for her!)
He has developed a very strong bond with my little ginger guy and it's tremendous to watch him melt when he's feeling awful because the little one knows he needs some cuddles!