I was serving in the army and went into a small library on a military base years ago, I must have been about 22 and dressed in short running shorts and honestly accidentally flashed the librarian as I crouched to look at a book. We were the only two in the small library, and she came up to ask if I needed a hand. She was way older than me but gorgeous with big boobs, and I got a little flustered as she stood there as my cock just went hard in about 10 seconds. It started poking out uncontrollably and far too obviously. It was like trying to hide a pole in a tent, not easy! It was quickly obvious, and eventually, I had to cover things up and go, and she clearly loved it.
I was very flustered by the experience and had decided never to go in that place again when guess who I bumped into at the NAAFI shop just the following week, yes, the same librarian with a shining smile and a warm, welcoming voice. All she said to me was, "I hope to see you back in the library in those short shorts, Wednesday afternoons are far too quiet". Well, that was an invitation I was not expecting, and Wednesdays were sports afternoons, so everyone went off to play football or whatever they did, and no one went to the library, so I did.
As I entered the library, my cock was already trying to escape from my short shorts due to my anticipation of what may happen. I walked in the door carrying my running jacket to hide the bulge my cock made. As soon as she saw me, she came straight over and welcomed me, glanced at my shorts, and said, "no sports this afternoon"? I stammered, nooo and as quick as a flash, she had taken my jacket and walked across to hang it on the coat stand! The head of my cock was already poking out of my shorts, and I think she saw it, so in a panic, I sat on a small stool near some books and pretended to be interested in them. Sitting down was a double-edged sword as it pushed the head of my cock out of the shorts, but if I clamped my legs together, she wouldn't see it, so that's what I did.