I'm 17 and never had a girlfriend, but often times after talking to a girl for a while, flirting, seeing her a few times (whether it be school, camp, or whatever it is), and becoming infatuated, i'll become jealous when she flirts with other guys. This is before there's even be a date, or any sort of sacrifice made from one other that would elicit this type of feeling from myself. I rarely act upon said jealousy because i know there isn't any reason for me to be jealous considering there is no relationship, but i still feel this shitty feeling inside that i absolutely hate. And it's not neccesarily out of oneitis because i feel just perfectly fine when I hit on other women, and I do take pleasure in it. It feels even selfish and self-centered for me to feel this jealousy, but nonetheless i do.

One current example: I'm currently at a 2 week summer camp about engineering. It started on monday, and this girl whom came to me during lunch, and initiated contact with me, seemed really into me. We talked a lot, and for the next two or three days i'd be the only person she really talked to (not out of shyness, just that she'd always be late and sit with me during activities). It got to the point were others thought she and I knew each other from before and were dating because of how much we'd talk and flirt. While occasionally hitting on some of the few other girls at camp, i still became pretty into this girl. Today, I realized that in reality i've been an orbiter. A victim of the type of girls who string dudes along for their benefit without any real intention of a relationship. She started talking to this guy, whose become a friend of mine and doesn't even have any interest in her, and she's been very clearly acting how she acted with me, but towards him, and seemingly at a higher level. I feel like she may be also just getting another 'orbiter' to friendzone, but I still felt like shit whenever i'd see them flirting. This jealousy gets me flustered and I feel like in an attempt to make myself not seem like i'm trying so desperately, i become more rigid with myself and not my normally care-free and social self. I tried messaging her yesterday and today through snapchat (which she did open, and she's always on her phone), to no response. I know not to continue paying this girl more attention than i should, as that's what all her guys do (she's said she friendzones a lot of guys and keeps them around for her benefit), and to just keep exploring all my other options, but that feeling of jealousy that's been reoccuring for me for a long time really hinders me. Any tips on how to learn to settle myself and not become so flustered and easily infatuated? What to do to get rid of this feeling?

TLDR: I become infatuated easily, and become irrationally jealous.