She's been with her boy for many years, they're both monogamy-leaning, want to be together... but he's got feelings for another woman too, and is very confused by this. So, she doesn't really know how to deal with this, he doesn't really know how to deal with this. She came to me, 'cause she knows I'm poly, and basically just wanted to hear that it /can/ work. I gave what little advice I could, and said I was happy to talk or help out in any way I could. I don't know how much help I was.
So, I come to you, reader. Any sage advice I should pass on to my friend as she tries to figure out What To Do?