Its when you take Mountain Dew and pour it in mouth( like 1/3 to a half of your mouth), you don't swallow it yet, you keep it in your mouth. You tilt you head back and then pour vodka in your mouth (like a shot or more) and swallow it like a shot. It tastes like all Mountain Dew, its amazing. Seriously, if you do it right, you can only taste the dew, its amazing.
Dude, try these Dew bombs, you can't even taste the vodka.