Why do diet coke and sour patch kids react?

Oh, dude, it's like a chemistry party in your mouth! So, the citric acid in Sour Patch Kids reacts with the Aspartame in Diet Coke, creating a little fizzy fireworks show. It's like a science experiment you can eat and drink at the same time. Just make sure to brush your teeth after, or you'll have a whole other reaction going on in there.