I've done some research as to products that are available that may solve one's need for a P.I. ; I was astounded as to what's available. For instance, you've all heard about computer software that tells you every website visited, and allows you toread every email sent or received. But did you know that to load this software onto the computer you want to spy on, all you have to do is email it to the person, it will be unmarked, and if the person opens the attached file, the software is then automatically loaded, and you will get emailed every time there is activity on that computer. I was astounded to learn that it is THAT easy to spy on someone.
There are also phone tap eqpt, and listening devices that record every conversation in a particular room of a dwelling.
So if your problem is with a SO, looking into this type of eqpt might be a better way to go.