A challenge where you put a bunch of mentos in your mouth and trying to consume a 2 liter bottle of diet coke spilling as little as possible. The chemical reaction produced by the coke interacting with the mentos causes it to burst out causing people to spill coke while consuming it.
When one takes a condom, fills it with diet coke and freezes it. The Diet Coke Condom can be used as a weapon for self-defense or as a dildo, it has other uses too.
The Diet Coke Condom was invented by popular manga bishonen schoolboy Rodrick Heffley as a weapon against his younger brother Manny-kun.
Rodrick has filled a condom with Diet Coke, froze it, and bashed Manny over the head with it. Manny has fucking died. The Diet Coke Condom is a deadly weapon.
Four magic words which completely completely invalidate your prior sentence, protecting you from calories, thus preventing you from feeling bad about the massive amount of fat and carbohydrates you're about to consume. Used after ordering food, especially fast food. This sentence is used much the same way as "No homo" and "But I'm not a racist" are used.
Cashier: "Welcome to McDonald's, how may I take your order?"
350 lbs: "Yes, I'd like a Big Mac, extra bacon, extra cheese, an order of twenty Chicken McNuggets with BBQ sauce, A McRib, A large order of fries, Two Chocolate chip cookies, and a McFlurrie with M&M's. And a Diet Coke. I have to watch my Blood sugar after all."