Simply stated, a pee-buddy is someone you enlist to help in your Graduated Exposure Therapy. Their role is to make things more challenging for you. Having a pee buddy can greatly accelerate your progress.
Graduated Exposure Therapy with a Pee Buddy
Lets say you currently can only use the bathroom at home when you know that nobody else is in the house, a pretty severe case of Shy Bladder. You enlist the help of your friend and neighbor "Bob" by explaining your condition to him. To your suprise it turns out he doesn't always find it easy to use the urinal and his sister suffers from anxiety, he is sympathetic and agrees to help.
You decide to meet on a Saturday. That morning you drink a quart of water and when Bob arrives you are ready to go.
To start with you get Bob to stand outside the front door with the door closed. That might be enough of a challenge for you to begin. You're able to go (but you don't totally relieve yourself!) so you ask Bob to stand inside the house right by the front door. Again, you're able to go.
By lunchtime you've drunk more water than you thought you'd ever drink in your life but now you are able to use the bathroom upstairs while Bob is watching TV downstairs.
Days, weeks or months later you and Bob go to the mall and you are able to stand next to Bob and pee quite naturally.
Ok. Things might not run that smoothly for you, there are likely to be sticking points and hurdles along the way but that is the general idea.
Why Having a Pee-buddy will help you beat Shy Bladder
One of the problems I have experienced in trying to tackle my Shy Bladder alone is that it's hard to get strangers to reproduce difficult situations for me.
For instance, I might be able to pee at a urinal when someone else is 2 urinals away but I need to practice with someone at the very next urinal. I can't ask a stranger "Hey Bud! Come over here and stand next to me!" (Okay, I could but I probably wouldn't live long) but if I have a sympathetic pee buddy he'll stand next to me and pee all day long and I will progress much faster.
If you have a brother, sister or best buddy who can be a pee buddy for you my advice is to try to enlist their help.
If you don't have a pee buddy
Don't worry, a pee-buddy isn't a necessity for progress. You can do it alone but it will likely take longer. Hey, you've already suffered with this thing for a few years most likely, a few extra months to beat this thing is bearable and you can do it.
Alternatively, the Shy Bladder Institute runs occasional workshops where you can meet other sufferers and act as pee-buddies over a weekend. People who have attended these workshops often report large improvements. The schedule can be read here.
Unfortunately, the cost is around $450 but the sessions in the US and Canada are led by Steven Soifer, the author of the book, and one of (if not the) leading expert on Shy Bladder so this could be money well spent and set you on the road to recovery.