A Spy Show is a special type of viewing. It lets members watch your private show in progress. But, the Spy Show viewer cannot communicate with you or the other users watching the show.
You can choose to allow or refuse members to spy on your private shows through the Private Show app, on the left side of your streaming window.
Spy Show viewers pay a fee, which you can set. This fee is on the viewer's Start button.
That's it.
Now you know how viewers can join a Spy Show.