The adjective describing "skjørt" in the Norwegian sentence is in its plural form, which means that we're dealing with the plural version of "skjørt" here.
korte skjørt = short skirts
et kort skjørt = a short skirt
can "hva som helst"="Whatever", "hvor som helst"="Wherever", and "naar som helst"="whenever"? Although in English I am pretty sure "whenever, whatever, and whenever" are similar, but not the same as "anything, anywhere, and anytime."