Hello, I need some perspective on my situation. Be as real as possible please. I'm a male 22.

I'm not sure I should let this girl (22) go. I was in a relationship with her for a year, then broke it off because I wanted to see new people. She ended up coming over my place one night shortly after I ended it, unannounced saying she wanted to get back with me and all this shit... we ended up fucking, but I never got back with her. She ended up coming around once or twice a month just to fuck and then she'd leave (this still happens two years later).

Within a short time after the breakup, I was also fucking another girl, but that ended after a few months. The other girl was a crazy ass bitch, and it seemed like both of them drove each other crazy (my ex and the new bitch). They knew each other through one of their mutual friends and both of them hated that I was fucking the other (I never told either of them I was looking for anything exclusive, but I guess they still hated it, even after I made it clear I'm fucking other girls). Both of them left shit in my apartment that made it obvious I wasn't being exclusive, too... which made things worse. I was also messing with and talking to other girls occasionally at bars and at work and shit, but nothing on a regular basis like these two.

Fast forward almost 2 years and I'm still hanging around with my ex, but only her. Every time she comes over, she buys me food, does chores for me, helps me, literally does everything I need and more. She dresses like a dime every time I see her, and almost always makes first point of contact. As of recently, the only thing she won't do is have a threesome with me and another broad. She also doesn't want to stick around if I'm fucking other girls, because "it drove her insane to know I was fucking other girls", so it's basically like we are in a relationship.

I've never had a threesome, but the sex is fucking amazing and has been for the past several years I've been talking to this girl, and gets better every time I've seen her. Sounds shallow, but this girl also has a head on her shoulders, and I can actually stand to be around her for longer than any girl I've actually met and talked with, too.

Tl;Dr: I know I have it really fucking good with this girl, but I'm not sure if it's worth it to look for more? I think my problem is that I want external validation from new girls, but I don't know if this is really the case, or I am just rationalizing?