I brought a stray kitten into my home and I also have two other kittens from my cats litter. The stray plays really rough! And I can tell that my female kitten does not enjoy it and sometimes it annoys the other kitten as well. I don't want to break his spirit, especially since he's finally joining in the fun with the other kittens, instead of just watching. He even gets our 1 y/o cat to play with him, any advice on how I can get him to play more gentle?