Do you remember that couple in high school? They never seemed really happy to see each other, but they had been off-again, on-again since junior high, and they just couldn't seem to be without each other.
I think that is maybe what Jethro and our cat have going on. The cat could easily get away from a toddler, but he never does. Jethro is eventually too rough, and the cat enevitably scratches him to get away. As predictable as this turn of events is they make no effort to avoid it.
Maybe that's all they've ever known, and they think that's how love goes between a cat and a boy.