I had a male cat for 3 years who was never around other cats. When I adopted him the shelter said he didn't get along with other cats. A year and a half ago, we wanted to adopt another cat. Of course we wound up getting two because the one we wanted had a sister (of course we couldn't take just one). So we introduced the male to two young and feisty girls. It was tough going at first. I mean tough! We tried everything to make the transition a smooth one. Separate rooms, brusing the new girls and then brushing the older male. It took time and there were rough moments, but those rough moments eventually turned into playing and now we have 3 loving cats. I never thought the male would get along with another cat, and that always prevented me from adopting more. But all it took was time (and patience) and it all worked out. Good luck!