This happened to me while in high school.
One day, in a break, I was rushing down the floor stairs. While I was coming close to ground and ready to make a U turn for the next set of stairs I just realized two of my class friends are just standing on the middle of the turn point and chatting. (1 m and 1 f) Because I was running and did not want to stop I decided to pass between them. But thanks to marble floor, while try to take my turn just through them my foot slipped. I know I was about to fall down and totally with a reflex I sway my hand to grab something, anything, to hold. And that thing tuned out to be the tit of my female class mate.
I literally grab her whole left breast to regain my balance. It happened so fast that even she realised what happened after all is over. of course knowing that was totally un-intentional she could not say anything.
For the curious ones; Among all other girls in our class she was one with big breats. Not soo big but when compared the other for that age she had pretty developed ones. Enough developed to help me stop my falling
