Mythical structure. A huge tower or monolith constructed entirely out of penis cheese. The possibility of its actual existence has been discussed in many an asinine debate amongst social circles whose activities revolve largely around the expansion of the mind by foreign substance.
"Behold, the smegmalith of legend. Fear not its godlike stature or life-taking effluvium"
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.