I attended many dances in junior high school; there was usually a dance once a month. This was in the early 1980s and my friends and I always looked forward to attending. I have many fond and vivid memories. In 7th grade I was slow dancing with my GF - at that time if you specifically invited a girl to a dance she was your "GF" We were dancing a slow dance, her arms thrown over my shoulders and my arms wrapped her waist, body to body. She was wearing a dress and I felt the waistband of her panties through the fabric. That sent me through the roof; I got a raging hardon. I backed away slightly, fearing she would feel it, but not far enough that another person could see it. I know she must of felt it, but nothing was ever said. We went to many dances that year, but "broke up" at the end of the year. We are still friends, though.
In 8th and 9th I had the same girlfriend. She was from a very religious background and I was always more cautious about getting too close to her while slow dancing. However, as members of student council we helped organize the dance and were given tasks to do before, during, and after the dance. Great deal - we did not have to pay to enter, and we got to spend more time together. What contact we lacked on the dance floor, was made up with these tasks. For example, trips to the supply closet to get cups, napkins, more snacks, etc - walking down a long, dark hallway holding hands and arriving at the small closet that we could just squeeze into together. Lots of brushing up against one another while reaching for items on shelves, etc. That led to our first kiss, and she actually planted it on me. That went on for two years. I must have gotten many hardons, perhaps she noticed, perhaps not. I do remember seeing her erect nipples a couple of times. Again, nothing was ever said. I would never have mentioned it to friends, for fear of it leaking out and embarrassing her and I am sure she felt the same way.
I remember those dances as exciting and always attended them. Saying 'goodnight' to her ask we left was painful because we enjoyed each other's company so much. I suppose there was a lot of sexual tension, but I do not know if we would have thought of it that way at the time. Incidentally, I am still friends with this woman, too.
By high school there were so many other activities that the school did not have dances. I did not care at the time, but looking back I really think those jr high dances were a great way to socialize with girls and do a bit of exploration.