Chris called him his kitten for a lot of reasons. He was excitable, jumping up and down and laughing, until Chris could imagine him chasing his own tail. If he'd had one.
He got pissy. Not often, but with full force, lashing out at people around him. It was then that only Chris could calm him, muttering soothing words and running gentle hands through his hair and along his shoulders. Petting him.
JC would nuzzle his nose along the underside of Chris' neck and settle himself into Chris' arms.
Chris called him his kitten. Mostly for the way he purred.