Purg and Barely....they would absolutely be devastated if something were to happen to you. They might continue to act "as if" they knew what they were doing all along, you know, all the justifications needed to cover the confusion and guilt, but they would know and suffer.
Saw this first hand. When I moved to US and my Dad was in Vietnam, they were in our type of a sitch. My Dad came home from Vietnam with a new wife, an American he met in Saigon and they moved to VA. Then my Mom got sick and died. My Dad still suffers the horrible sense of what was unfinished business and it was 30 yrs ago. Still regrest it to this day.
These H's of yours are playing with fire....and they can't help themselves at present...and are risking losing the greatest of gifts (you) they had in their lives. I hope they can wake up. I've seen how it can end otherwise.