|1.||Gym Floor Syndrome|
When taking tests in middle school and high school PE classes and you're forced to lay down on the floor, the floor is often cold enough that it causes female's nipples to stiffen up, and male's penises to become erect. The males seeing the results of the female's condition only worsens the male's response to the syndrome.
Often referred to as 'GFS' in passing.
Guy 1: Did you check out Becky's Gym Floor Syndrome?
Guy 2: I know, and thanks to that it's gonna be after lunch before my own GFS goes away.