I recommend that you and your boyfriend clearly identify and talk about the "weird feelings". Is it fear of loss? Is it jealousy? What is this "weird feeling"? What thoughts or beliefs underlie it? Are those beliefs / thoughts true? Where did these thoughts / beliefs come from?
I also recommend that you read articles and books on polyamory, if poly is what you want to explore.
Learn how to express your needs, desires, fears... with one another and to talk about these things as allies in a growthful journey.