Ha ha! That's classic, the half-in half-out, cats are well-known for it, aren't they? Oh! How sweet they sound to be, and they are so pretty too! Still very playful, and good friends, that's what you want! Our Thomas was at least 3 years old when we got Suki, because he was depressed after our son moved away. SHE wanted to play much more than he did, and SHE demanded attention and affection, but fortunately he is a mellow fellow and was very patient with her. Being her new "mother" was just what he needed. Best little investment we made, she pulled him right out of his withdrawal and sadness! They are good friends now and mirror one another's nap times, groom each other, and enjoy noisy play fights every day! In our kitties' case, they need the companionship of another cat to be truly happy. As your babies get older, I'm betting they will enjoy whatever they do, as long as they are doing it together! (And with you of course!)