So Atlas and his newly (as of a month ago) adopted sister Scout are getting along great. We frequently have to get them to calm down, as we worry that their constant running around the apartment will bother the neighbors.
The only adjustment problem we've had with Atlas, is that he gets very jealous of Scout, when we come home and they both want to greet us.
That and he did something tonight that's he's never done, he peed in Scouts food bowl after she was done eating.
He hasn't had an accident in a very long time (at least three weeks or so) which is a big change for him because he usually would have a slip up a few times a month.
This was definitely not an "accident" they both finished eating, and he proceeded to lift up his leg and pee into the bowl (his aim was pretty good too I should add!)
Marking is a behavior we would definitely want to discourage, and if anyone has some tips on how to prevent this behavior it would much appreciated.