Haleivi – I got a different impression of what the OP was asking. I had a ben bayis who was a solid BT. Solid, meaning secure in frumkeit. He was getting married to someone who was also a BT and secure in her frumkeit. The boy and I were discussing just how much detail is important to discuss. The kallah knows he had a secular past but she may not know just what type of recreation he was into. She may assume he had taken drugs, but maybe she would never have assumed heroin use. It isn’t that the spouse doesn’t know that there were indiscretions, it is about providing detail of the amount and nature.
Along those same lines I had a friend who was from a BY family but was very promiscuous in high school. She married a very solid straight boy from a very good yeshiva many years later. I asked her if he knew about her ‘past’. She told me that he knew she was sent away for high school and what that implied but not the details. It wouldn’t be right for him to think it never happened, but he may not need to know the specifics.