Went camping with another family. The shower blocks were outside, and felt open air, although nobody can see in. I went to have a shower, and the water was taking ages to get hot. So standing there naked knowing an entire field of people was on the other side of the door, I got hard and decided to stroke my cock. I shot a load hard across the stall onto the back wall, then washed it off and had my shower.

When I had re-dressed and came out the door, I realised the other wife we were with had been in the stall next door to mine the entire time. She came out and had no idea. I'd just emptied my balls with her washing her naked body the other side of the wood panelling.