When two people are making out and come apart for air and their sticky slimy slobber stays stuck together and they suck it right back in after getting air.
Someone needs to throw ice on the two St. Bernarding over there. Ewww gross did you see them suck their slobber back in?
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.