Schuster and Grace have been together now for nearly 9 months. During that time, there has never been any aggression shown. Just here recently, I've noticed that when he and Grace "play", he will grab ahold of her tail and won't let go, and sometimes even pull her tail. I've noticed that he don't just up and do this, but he will do this when they wrestle with each other or when she jumps up on him. She doesn't seem to act like it hurts, she doesn't cry or wimper when he does it.... it's like it bothers me more than her.... I've not got after him for doing this YET, but if she acts like it hurts her than I'll sternly tell him NO. any advice or opinion?