I only had two cats, Katie and Gracie, for many years, then fell in love with and adorable, yet very timid, 6-month-old gray/white male kitten that no one else seemed to want. Enter Peter. Although he drove my older girls nuts, they accepted him without too much fuss. What really surprised me was how quickly Katie took to Pete, despite an 11-year age difference. Gracie's still not thrilled with him (but she's not thrilled with other cats period), but they definitely have a "big sister, little brother" kind of relationship. I would have happily left it at three cats, but when Claire (who's Pete's littermate) lost her owner unexpectedly, adopting her was absolutely the right decision. She and Pete were happily reunited and are so sweet together.