He risk that someone will find out her secret desires and embarrass her. The risk that she could be hurt by her partner. A special trust is required before you can open up and share mother son incest you fantasies with someone. And then there is the risk of tying yourself up, and not being able to get free. But she had no really close friends, no one she could trust, so she had invented a "safety person". A close friend who had a key to her house and could save her if her something went wrong with her bondage, her self-bondage. If she was unable to escape after her orgasmic fantasy, her unknowing friend would be over sometime later to help here get free. This was the way she incest family felt. It had been her secret until now.........