That's really fucking hot! I don't know how she would've not recognized that it wasn't your cock, but either way I'm jealous. I love sucking cock and getting sucked at adult theater glory holes, and would give anything for my wife to be into it too.
My wife and I were at the gloryhole in Corvallis one time and had shared a couple of cocks. After waiting for about 15 minutes for cock, she asked me if I would go to the next booth so she could suck my cock through the gloryhole. She likes sucking strange cock. As I was walking out the door, a guy walked into the booth. 10 minutes later he came out and I went back to the booth my wife was in. She never knew until I told her that she had just sucked and drained a "strange cock."