Kitten Update
Not a kitten anymore.
It's been roughly a year now, and things are going well with Lennie. Initially, we were told Lennie was a girl, hence the name Lenore, but then we found out it was a boy. They missed a couple of bits because of his long hair.
He still has boundless energy and loves disrupting quiet time for the other two, but generally, he is doing great. The other cats have softened to him, but only to the point where they don't leave the room when he comes in. They get along, though.