I think jealousy is a dark force, so although I think it, I run from it, and act like I am not jealous when I feel like I am. I think I am a superior catch, so if a girl is interacting with me and she is also interacting with another guy, I will give her to the other guy to see how smart she is. If she goes with him she is stupid, if she goes with me, she is smart.
I just had to give up on being jealous, I know for me it was that I was insecure in who I was and it just hurt my relationships. I would always say some thing and then regret it because it just sounded so stupid later. I am not saying give up on your crush but reinforce with positive acts that shows you as a better person that to stoop to being like that.