I will talk with my wife about her coming into my house with out permission if she does it again and I have another reaction to it. I will not go into her new place uninvited. I realize this is our place but she did walk out of it. If I feel like it is an invasion of my privacy then I will say something.
This is something I talked to my W about as well, because she was coming over and walking in unannounced. I told her that I wanted her to start knocking and I would let her in. She did start doing that, but over time it's kind of been relaxed because usually the kids are with her and it doesn't make sense to make all the kids wait outside for me to answer the door because it IS their house too and they do come and go as they please (as it should be). Now if she's alone she knocks and then let's herself in and announces that she's there. That's OK with me, it's not a big deal to me now like it was when we first separated.