@cantkillfaith In her mind she is "the girlfriend". You have some "gender blindness" going on. From a biological perspective, for a man, sharing a woman could mean cuckoldry and that his genetic legacy (which is what our soupy primordial brains obsess about) could get snuffed in favor of another man's. For a woman, agreeing to an open (on the man's end) relationship will give her access to a higher value man. It's a trade off. She can have ALL of Billy Beta or some fraction of Alan Alpha. That may not be her preference, but it can be how she resolves her situation.

This is also, incidentally, why we recoil from MMF threesomes and women are much more open to FFM threesomes. We are The Prize; they negotiate access to us (this is the reverse of the mainstream thought process, but that is mere supplication.)

As another real life example, my primary slave girl (well-adjusted, ivy educated, father present in the home growing up, no apparent traumas) happily submits herself to me an any way I desire. Why? Because her Wetware wants access to a high-status male, and is willing to trade anything to get it. She would PREFER, on some level, that we were exclusive, but, to her, the value of having a man who understands her psychological need to submit is greater than her her desire for monogamy with a lesser man. IOW, she's finally getting hit right, and isn't going to give that up.

@3x7r3m157 This is the correct answer.

Guys pussy out and give commitment, because they are afraid of losing a particular girl, and then they want to bang other girls because: there are other girls, but are afraid of losing the girl they committed to. That reeks of "testicular fortitude deficit". The proper thing to do is to keep the OLTR relationship "OPEN" on your side and then bang your side chicks at your leisure.

So you either have to OLTR up a woman who is bi and down to share girls, as @itiswr1tten has done, or OLTR a girl who will tolerate your indiscretions, even if she knows she is lying to herself (ex. my OLTR and I have an "understanding" which is that she understands that she isn't going to "understand" that I fuck other girls. My slave girl knows she's the side chick but isn't ever going to ultimatum me because she's afraid of losing access to me - so she's the 'beta' in this case - and when other girls ask for exclusivity I say, "Sure, except for girls we share." which puts them on notice that the answer is "No, unless you are down for Girl-Girl-Vasya 3ways".)

@cantkillfaith probably has to lose the current girl to (a) learn this and (b) set it up going forward, unless she is secretly bi, in which case it might work. Otherwise, it's time to nut-up or shut up.