finding a swinging couple or taking a girl home for sex is different than poly... your girlfriend is talking about something almost completely different. I would suggest being very careful no to confuse your feelings with her words. You might "fall in love" often and easily, but she might not and bringing someone home or swinging might not work for you as you seem to have emotional connections easily. Sex for fun and sport, is just that, no emotions arise other than friendly fun. There can be a huge difference.
I think it sounds like you need to start talking and clarifying your thoughts on this. Perhaps doing some reading on here will help. Find some threads that really speak to you and then talk to your girlfriend... send her a link to them maybe or find other stuff on line that suits your way of describing yourself. You never know what will happen. One thing is for sure, you don't seem to be able to stay where you are in your head. Time to move maybe? If it works out with her then great, but if not, it wasn't meant to be and you can start off fresh with a new approach. That is hard to think about, but, perhaps that is the destiny that is for you.
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