Coke In a Straw

I had my usual breakfast today at Brueggers Bagels: a cinnamon-raisin bagel, peanut butter, and Diet Coke. I went home with a full 20 oz cup of Diet Coke. By the time I got home, a bit of Coke had worked its way up the straw. It looked interesting so I took a picture of it. I used a flashlight to help with lighting.