Well, as fate would have it, the two of them have called it off. He had been hesitating for a while. He would send her flirty, dirty texts at night, but at work or at lunch, he was ice cold. Turns out he just couldn't wrap his head around how or why I would be OK with him and her being together. She never told him about my moments of fear or hesitation. She is super pissed at him now, because for two weeks they had been going back and forth and building it all up, only to have it end with him turning her away.
I'm so proud of her though. She easily could have lied to the guy, told him that we were unhappy and that she wanted to cheat on me in order to get what she wanted, but she stuck with openness and honesty. Not only with me, but with him. He just couldn't handle it, nor be man enough to tell her at the onset, or a week latter, or even in person.
I feel really bad for her since she is now very hurt and embarrassed. It was very interesting to be with her and help talk her through, essentially, a breakup.
Despite the failure of this relationship, she is committed to "trying it" with someone else. It's an experience that she wants to have, and still, so do I. She isn't sure who though. I think she needs to stay away from work, but she doesn't like the idea of meeting someone online. I personally would like to know the guy more than I did this guy, but I think she wants to still keep it separate. That's another conversation, however.
I think we both learned a lot from this experience. I know I did. I'm sure when the time comes for her to be with someone else, I will have similar fears, but I think I'm more equipped now to handle them.
Thank you for the kind words. I think I'll stick around!