A play on the words "first come, first served" which appears on a banner advertising the "Temple of Eros Annual Orgy and Buffet" in the Mel Brooks film "History of the World, Part I".
I was searching for the classic film "One girl, two cups" when I stumbled on this phrase, which appears during a scene set at a Roman bazaar/ "First served, first come" at an orgy is humorously playing on the original phrase "first come, first served" in retail or the related "first in, first out" in accounting or computing science.
First-come, first-served (FCFS) – sometimes first-in, first-served and first-come, first choice – whereby the requests of customers or clients are attended to in the order that they arrived, without other biases or preferences.
There's some nice cake over there, firstcome first serve!
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.