Definition:
The act of revisiting the past to fulfil a romantic or sexual desire that was left unresolved at the time, before returning to the present. The expression describes the satisfaction of correcting a missed opportunity by metaphorically travelling back in time.
Origin:
The expression originates from the Danish comedy series Klovn, specifically the fourth episode of its ninth season, titled Alter Ego. The term is introduced by Casper Christensen and references Marty McFly, the protagonist of the Back to the Future film trilogy, whose adventures involve travelling between different periods in time.
"After reconnecting with his former high school crush and finally taking her on a date, he proudly declared that he had just experienced McFlysex."
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.