Thanks for the responses. I know that my issue stems from insecurity. I have no problem stating that. I don't claim to be perfect, enlightened, and certainly not better than anyone else. I own up to my jealousy. I know it's a huge problem in my life. I wish it wasn't a part of who I am, but lying about it would be just that -- lying! I'm big on honesty. I try to evaluate my feelings and actions as fairly as I can, and to pinpoint when I'm being a big jerkface.
I guess I'm more interested in how I can overcome this jealousy... Is there anyone out there that's had major jealousy/insecurity issues to overcome? If not, is there anyone in a poly situation who is not exclusive but their partner is? How has it impacted your relationship?