One summer day I happened to come across one of my kid's high school teachers walking down the sidewalk and we walked together for a bit. She was attractive and generally well built, without being distracting. But on this warm day she was wearing a deep green satin blouse without a bra. Her breasts moved in a slow rhythm to her step - not overdone, but definitely with some momentum. Her nipples had been played by the satin and were hard as bullets.
She was a little embarrassed by it and I said something friendly and vanilla, like "hey - beauty is beauty no matter where we find it". But I was so hard I thought I would cum in my pants - it was obvious. You could probably have seem my dick straining from across the street. We parted ways, both acutely aware of how our bodies were reacting to each other. The rest of the day I couldn't keep that vision out of my head and finally went to a restroom and milked myself dry. Damn!
Kind of a Jennifer Aniston effect.