ok so when we brought cinnamon home, it was a nightmare. now things have soooo much improved. However, there is sill some growing, an occasional hiss (from mittens usually of course) like when I feed them together, mitten does not like that or if im holding mittens near cinnamon she does not like being held when she is too close but mostly everything has been pretty good. and it SEEMS like they might be playing but I cant tell, they will chase each other all around the living room and play "hide and seek" in the curtains which is pretty funny or one will stick her paws under the door and the other tries to catch em. however, mittens still swats at cinnamon all the time! its not very aggressive no claws or anything but she does it so often or she will pounce on her from behind or what not and just chase her. now mittens much smaller then cinnamon and while her demnor and personality is much more docile then mittens and is willing to take quite a bit from mittens, she will hiss or hit back when cornered which is happened a few times at first so I know she CAN hold her own, but she just seems to let it happen one night they were playing and it was getting quite loud and over excited I thought, (it seems that as they play mittens will get spooked or whatnot and growl and lash out a little or whatever) I came and got cinnamon and brought her to our room thinking she might be scared but she got right back up and went to mittens. I have even mittens get out of bed, go to cinnamon who was on our bed, the two touch noses and run off to play! how can I tell if this is playing? now some times it seems cinnamon is scared or sad a little, she will be a little crouched but because we have only had her about two weeks I don't really know her that well and she seems like that a lot of the time (I call her eeyore because she kinda has a sad, slow look to her although she is quite cute!) but like a said she could run and hide or fight but doesn't. I know she does not like when mittens gets upset when the are eating and shrinks back. sorry to be so everywhere but that is how they behave, so up and down!