Kicking back legs?
My new little boy Chi named Angus is doing something that looks very funny to me, while playing with my female Chi. During play, he turns his backside to her face and starts "pawing" at the carpet and kicking up his back legs. It looks like something a bull would do to a matador. (Does this make sense?) I've read it's a sign of aggression, but they are being very playful and he is naturally a very submissive dog. He has been neutered - my female has not been spayed yet.