You're pretty lucky that Jake likes headscritches of any sort, much like a dog, or he'd likely have been put off that you were treating him as though he were one. He made a sort of inquisitive grunting sound at that, moving farther down and giving a more confident sucking motion as he pulled back and scooted back down. That was how it always worked in the few dirty videos he'd watched (and yes, despite his age they were few). It wasn't quite a bob, but it was working up to it.