You’re in a tough situation because you want to keep your long-term girlfriend from knowing about your mistress, so that you can figure out if your mistress is a woman you want to break up with your long term girlfriend for, but the only reason you want to figure out if your mistress is a woman you want to break up with your long term girlfriend for, is because you just learned she’s dating someone. 🙄 I think you’re jealous.
I don’t think that dating your mistress any more than you already have is going to convince you to leave your long term girlfriend. In fact, I think you are pretty clear that you don’t want to lose your long term girlfriend — but you want your mistress to be monogamous to you. But, you’ve already noted that your mistress won’t leave her new boyfriend as long as she knows you’re not going to leave your long term girlfriend, so you’re basically in a stalemate. 😯
The most you can hope for is that your mistress will be willing to date you on the side while she maintains her relationship with her boyfriend who doesn’t know about you, and that your long term girlfriend won’t find out you’re cheating. I don’t think that, realistically, you can hope for more.
When women start having sex with a man, they usually stay bonded to him, as your long term girlfriend is to you. Men don’t always have the same instincts, and you clearly don’t. But you have to understand that your mistress is probably going to bond monogamously with her boyfriend and not be interested in you unless you break up with your long term girlfriend and make yourself available to her exclusively — which you’re not willing to do.
Under the circumstances, I think your best bet is to stay with your long term girlfriend and let your mistress alone so she can have a relationship with her new boyfriend without your interfering.
