First off, look at dirty sanchez and pay close attention to the definition that says u wipe the poop with ur finger or thumb, now this is basically the same except u take your 2 pinkys and make a French type moustasche on her face and could even be equipped with the proper French noises.
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.