Without going into great detail, I will tell you that I fell in love with an older, married man at my place of work. He had a terrible relationship with his wife; in fact, the woman was known around the office by various crude descriptions, and he came to the office every day with a new horror story of her mental/physical cruelty to him and his children. As I worked alongside him I became a moral support (I use the word "moral" loosely, sad to say) and we became close. Very close. Sigh. It's a very ugly story and I'm not proud to tell it. Anyway, the short version is this: his wife discovered that he was planning to leave her, and suddenly after a decade of misery, she decided she wanted him to stay. She entered counseling both with and without him. At first he didn't believe that she could change, but he very soon realized that she was going to make a sincere effort. That was when I, his "soulmate" and "true wife" and "love of (his) life" suddenly became disposable. And he was gone. No calls, email blocked, nada. Gone.
I'm not saying I didn't deserve this treatment. I'm not saying that at all. But I will tell you that it has been the most painful experience of my life and I ended up in the psychiatrist's office and on medication. Right now I think I will never recover. I hope I'm wrong.
Why am I telling you this? Because your situation does not involve merely yourself and your wife. There are the feelings of this other young lady to consider. No doubt you recognize this on some level, but how thoroughly have you thought it through? Because I can tell you, she really doesn't deserve to get caught up in the middle of your marital problems... I tell you this with all due compassion and respect for your position.
Thanks for reading.