A magic dump is one that makes you feel alot better. Say for example you have an awful tummy ache and then you poop and it goes away, you just took a magic dump.
My stomach cramps were so awful I thought I was going to die til I took that magic dump.
Right as you are about the climax while vaginally fucking a girl, pull out, cum in her bellybutton, twist both of her nipples and give her a wife-beating slap in the face to open up a magic portal that leads straight into her stomach.
You: Dude I used the Magic Cum Dump on my sister last night
Your dad: Atta Boy Cletus
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.