the chaperoning teachers were disgusted by the large cluster of 15 year olds grinding each other on the dance floor at the homecoming dance
in high school: a meaningless football game, followed by a clothed [orgy] containing mostly lowerclassman
"the chaperoning teachers were disgusted by the large cluster of 15 year olds grinding each other on the dance floor at the homecoming dance" What is the definition of "homecoming"?