EDIT2: Thank you everyone, you've been very helpful.

EDIT: Why the downvotes? I'm relatively new (read the required reading), but I still have my questions. What would you do?

tl;dr Possible oneitis

My LTR of three years is pretty damn good. I've been with a few girls and my current girlfriend is fantastic. She cooks, cleans, she's my sexual playtoy whenever/however I want, smart, young, etc. I could go into further details why what we've got going is great, but I'll spare you the mush.

My question is: how do you spin plates in an LTR? I now know should I start a new relationship to establish that yes, I will talk to other women, and yes I'll be pulling phone numbers.

Obviously, I did not establish those boundaries when I started dating her almost four years ago and even if I talk to other girls she gets a little jealous.

We have a very open and honest line of communication, something I consider paramount to a good relationship (of any kind) and should I get girls' phone numbers with the intent of sexual pursuit, I would be obligated to tell her; even if I didn't, she would find out because she runs through my phone occasionally. My past behavior when we weren't official was player status - and she knows.

If I'm being honest with y'all, I look through her phone occasionally too. I'm not worried she'd cheat, but I'm protective and offensive towards any guys she's chatting with. I'm easily made jealous too.

Problem: Possibly oneitis. I'm not outcome independent. I know that if I lost her tomorrow, I'd lose a lot. My best friend, my confidant, my lover.

Solution: Plates, right? I can't be dishonest with her, but she would despise me if I regularly and actively pursued other women. I'm assuming TRP would not recommend trying to "explain" to her my situation because she simply wouldn't get it.