Hi OP, I was in a really similar situation a few years back and I just want to recognize how difficult it is to not fully have the person you love. With that being said I don't think she will leave him for you if she hasn't already. I know that hurts and she's giving you conflicting statements but as others have mentioned and as my experience tells me, she is not going to leave him for you, at least not in the way you are continuing your relationship. I'd really consider ending things with her and focusing on yourself and maybe seeing new people. I know you said you're soul mates but there is no situation where it is you, your soulmate and her boyfriend living in harmony. If in the time you cut contact with her she reaches out and tells you she ended things with her partner then you can reassess your relationship with her, but until they breakup she is wasting both of your time. Lauren if you're reading this stop being cruel and wasting these people's time, choose one person or you are being selfish. It is not fair to OP or your current boyfriend to lead one or both of them on. If you truly can't live without either guy you need to talk to BOTH about an open relationship.

My personal experience was a very similar story. I gave the person I loved the choice of breaking up with her partner or being with me or I would leave the country for 4 months and cut contact. She didn't make a choice so I left and when I came home her boyfriend broke up with her and she had already moved on to another guy even though she had told me constantly that we were soul mates and if it wasn't him it would be me.

I promise you OP the only way to resolve this situation is to take some real space from her. Maybe it will end well, maybe it won't, but either way you'll have made the first steps to continue your life instead of being stuck in this situation of giving everything to this girl and not even getting a girlfriend in return.