One of my favorite memories of flashing was when I was dating my girlfriend, now wife. She had put on a fairly decent scooped necked top, and as it was a hot day and unbeknownst to me she had decided not to wear a bra. She was a perky 34b cup at the time and could get away with it. We went round a friends house and were discussing bikes as our friend had bought a really expensive new one. The guys all had a go on it, and it was great.
My girlfriend announced that she had not ridden a bike for years, and without thinking I encouraged her to have a go. She was unsure, and so we all gathered round the bike to help her get on. As she got on of course she had to lean right forward towards the handle bars. The top fell forward and I could not believe that suddenly I was standing with 3 mates, with my girlfriend on a bike and her breasts were completely exposed. We were all standing around her looking down at her and you could literally see the whole of her breasts, on one side it slipped down below the nipple.
She was a bit shy at that time and I could not believe that she knew that she was exposing herself in this way, I was about to tell her she better get off when she rode off up the road. She was concentrating so hard on not falling off that she then rode around for 5 mins. Every time she turned back towards us, once again her shapely tits were shown off again wobbling lightly in the breeze.
I kept telling her to get off but by this time she was enjoying herself and thought I was being boring. My mates looked over a couple of times at me with huge grins but what could I do?
Once she got off, I did mention to her that her top had been a bit exposing but she just laughed and ignored me.
Looking back on it now is of course a complete turn on, although she still denies knowing anything about it.
I had a somewhat similar experience years ago with my now ex.
She wore a loose fitting blouse with no bra, I had a few friends over and she bent over enough that her breasts were completely exposed several times.
Later when everyone was gone I asked her if she realized that they had all seen her breasts very clearly.
She said she knew full well they had seen them, it was her intention all along.
