I have noticed that Wellington has very strange movements when kneading. He kneads away with his front paws but every few moments his back legs sort of twitch and it is almost as if he is trying to spray, though nothing comes out (sorry if this sounds gross). He only ever does it when kneading on me, usually when I am lying down. I do not think I have ever seen this before, and certainly the girls don't do it. I cannot remember ever seeing or at least noticing, a male cat do it either. Does anyone have anything similar in their experience, and what does it mean?