When I had a kitty that slept on me, if I wanted to turn over, I would put my arms under the blanket and lift her up in a sort of makeshift cat-hammock and turn my body underneath, then set her back down. She didn't mind it. But if I moved in a way that she wasn't sure was intentional, she would firmly tap the body part in question with her paw, three times. I miss that girl so much.