So I've been seeing this girl for a few months and we agreed to no feelings from the start, we also agreed to exclusivity.

She told me she wants to see other people as she wants a serious relationship, I broke frame and told her to come pick her stuff up because I'm not putting up with this shit. She came over and we fucked, she ended up staying for the whole weekend as it was my birthday and I had some friends over.

I ended up agreeing to seeing other people and stopping as soon as one of us fucks someone else. I'll start working on building a rotation of plates.

My plan was just demoting her to a plate, only using her for sex and not doing sleepovers and hanging out anymore, and just act colder to her in general.

However I feel like I lost frame twice by losing my shit over her wanting to see other people, and also by agreeing to her offer. Is it worth keeping her around or should I just stop seeing her?