I once knew a male and female couple. For my tastes, he was a bit too literal when it comes to scripture. But no serious warning signs. Both seemed like fine people. They came with a great back story. As I remember, she left an abusive relationship with with prepubescent daughter. He kind of swooped in and rescued her like a night in shinning armor. So my wife and I kind of double dated with kids in tow.
Out of the blue, the woman told me she was leaving her husband because he had been raping her daughter for years. At first I thought no way. Later I learned he confessed to his pastor. His penance was to repeat his confession to the authorities. He did. Again, at first I thought no way.
He then went to prison and she moved to Australia. Again, at first I thought no way. Now I know monsters are really good at hiding.