When a man, gay or otherwise, has anal sex with at least 3 or 4 other men throughout the same day and night. Girls can be count as part of the mud run, but the one making the run is always a guy.
Guy 1: You guys wanna come over this weekend for a BBQ, some drinks and then maybe a mud run.
Guy 2: Ah, yeah, that could be fun. I've never done a mud run before.
Guy 1: You don't know what you're missing. You can even bring a couple of girls along, just not too many.
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.