The faux illness your girlfriend/boyfriend gets on a weekend night preventing you from going to meet up with your friends as originally planned.
Dude 1: Didn't Mess say he was coming tonight?
Dude 2: Naw, his girlfriend caught the Friday Night Flu.
Dude 2: Naw, his girlfriend caught the Friday Night Flu.
by HairySally February 01, 2008
When you spouse gets sick on Friday so you have to watch the kids all weekend. Usually last two days.
by Herod apyur pupir February 24, 2017