Here's one experience I had:

I see a glory hole booth and think "why not?" I read the sign that says "ring bell for service" and ring the bell. The booth is set up so that I can see the other person from the neck down and they can only see me from the waist down.

Moments after ringing the bell, a large naked older man comes enters the booth. As I'm figuring out what's going on, he reaches through the hole and lightly strokes my penis.

I tell him "Uh...I think I've changed my mind" and flee.