The blindfold and anonymous aspects of a gangbang are definitely something we find very stimulating and erotic.
Our first exploration of this scenario was back in 2006. I had privately invited six of our neighbors over one evening and convinced my wife to sit on the living room floor while completely nude and blindfolded during their visit. She was excited but had no idea who I had invited.
When the guys arrived I had already told them that they could have fun with my wife but to keep things completely anonymous they could not talk or speak so that she would not recognize any of their voices. My wife could have easily removed her blindfold to peek, but she liked the idea of not knowing.
To this day, she still has not ever been told who the six men were that night. She sees most of these guys routinely, but can only wonder if they have seen her naked or had sex with her.
This was her on a blanket on the living room floor after the guys were all finished.
When my wife saw this image, she thought she would find one of the guys, she watched to see if any of my friends wore the shoes that were in the picture. She never thought about looking at any of our neighbors to see if they owned the shoes.