Drop the cum dump means jerking off or masturbating, and yeah... i don't think it's a better way to say you want to jerk off today either, but still...
Ay bro, imma drop the cum dump in 30 minutes, i'll be back alright?
An End of the World Dump is a sudden, intense poop that strikes usually at an inconvenient time such as at work or with company. It's an uncomfortable and hefty number 2 that results in a large and explosive shit, so powerful that it feels like the end of the world.
"Jeff, where did you go? We were in the middle of dinner."
"Sorry, the curry from lunch caught up with me. I had an End of the World Dump. You might not wanna go in the bathroom for awhile."