What is flip up Friday?

A junior high hallway activity where girls were subject to having their skirts lifted from behind in order to see their pantys. Giggling and running to the safety of the girl’s bathroom was the usual response. Occasionally she might turn and glare. Many wore shorts under their skirts to thwart the boys. This was common in the Tacoma WA are in the late 1950s and early 1960s.