Looking for some insight or any type of opinion on this kind of situation.

Have been seeing this girl about 4 months. Pretty attractive, good sex, intelligent etc. started out as friends then lead to a plate and was able to get sex almost after every encounter. She asked to be exclusive maybe a month or so in. Have been seeing her close to 4-5 times a week. Essentially this plate has become a no label girlfriend because neither I or her want anything more at the time. We act, talk, have sex, look and it feels like we’re dating. I would say I have a bit of oneitis for this chick and def feel attachment and wondering what I can do. This isn’t my girlfriend, however it’s to the point where I for sure would be bothered if she saw someone else or entertained something else.

I am just so lost on how does one behave in a situation where my relationship with a plate feels like a relationship however neither of us want that? Do I establish boundaries or do I go about attempting to not care what happens ?