lgbg,
Thank you for sharing that horror story, as painful as it must have been.
One point worth commenting on is that it makes little difference that he was unmarried. Even if he was married, the horror of such a setup would be all the same. The fact that she was married makes this such a horrific situation.
Indeed the entire situation would be unfortunate and unacceptable even if both of them were unmarried, as it would constitute a terrible breach of tzinius. All the more, of course, since she is married.