Dear Heart all I can offer is the feelings of a man on the recieving end of the news of an unfaithful spouse. There is no dagger, no sword, no impact from a speeding bullet that can match the pain of being hit with that realization. It boils down to her priorities, is she more concerned with pursuit of her own feelings or concerns for his? Marriage is difficult even when both halves are together, distance only complicates things. All you can really do is tell her to make damn sure she knows what she wants before she makes a decision, once it's done.. that's it. I wish the best for you and them both.

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As to marriage or celibacy, let a man take which course he will. He will be sure to repent - Socrates

Love is not looking in each other's eyes, but looking together in the same direction - Antoine De Saint-Exupery