When a female didn't wipe too well, then someone fucks her doggy style. As the ass is bouncin, the resulting shit stain on the male pelvis is a dirty Hershey kiss.
"Man, it was going great, till she got on all fours and gave me a dirty Hershey kiss"
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.