I posted a few days ago about adopting a new addition, Mercury, and that even after scent swapping before hand, things were still really dramatic. We've had the new addition in our master bath since we got him, trying to continue scent swapping. I brought down the blanket he'd been using and Leo has come around, he snuggled the blanket and figured out that his new buddy was nice and we introduced them one on one and they get along fabulously. Far form best buddies of course but they play together and lay together and such, no hissing, growling or puffy tails/arched backs. Our oldest however, Nova, is still very much against Mercury so Leo only gets playtime with him when the upstairs is closed off so that Mercury can't get downstairs. When Nova found the blanket he immediately hissed, arched his back and spat. He still growls at my husband and I if we call him by name, though if we offer him food or to go in or out he remains docile yet tense. He doesn't growl at Leo to much anymore but he still won't allow him on the couch or chairs, is he trying to reestablish dominance? He wants to stay outside all the time, my husband and I used to be able to pick him up or sit down next to him and he would cuddle in our laps. Now he only comes around if we are asleep and he'll hunker down between us though we can now walk past him without him getting upset. One thing I have noticed is that he stays near our son if he is in the house, not threateningly or anything, just sticking closer to him than he did before, which is saying something because he has always been very protective of our son from the day we brought him home. When we adopted Leo, our son had not been born yet, I was still 8 months pregnant at the time, and there were only a few days of low growls and occasional hisses before they were best buds. Could our son being in the house this time around have something to do with such a drastic difference in reaction? I have never heard of this but is it possible?