When one mate in a marrital commitment is caught by a third party trying to remove their wedding ring in contemplating approaching someone with the intent of breaking the wedding vow. In short, the intention of cheating on the other spouse. The action of removing the ring is caught and approached by the prospect, and the return excuse by the married member is: "I was turning the stone up", referring to the embedded stone in the ring and positioning the ring to display the stone topside!
Bob was at the bar and was caught "turning the stone up" by a hot female he just met! She asked what he was doing when he was trying to remove his wedding ring on approach.