My question involves non-married separation and possession law for the State of: Oregon

I own my own home in the state of Oregon. Recently I discovered my significant other had been cheating on me, so I kicked them out of my home. We had a discussion a few days ago about how we were going to separate our personal property, and I was, at that time, under the impression that we'd come to an agreement.

Today, however, they decided they wanted my camera because they were using it for a project, and when I told them no, it devolved into an argument that ended with them threatening to take the dog and other belongings not previously agreed upon.

My question is this; what rights do I have in regards to personal possessions still within my home, and what rights do they have to those possessions? Does there need to be proof of purchase on their end before I am required to relinquish any belongings? Am I within my rights to deny them possession of anything within my home?