A catastrophe caused by girl creating a problem where the guy takes the blame. It generaly leave the guy flabergastered.
Example 1:
GF: I'm pregnant.
BF: You're pregnant?
GF: Yes, and I'm keeping it. I never want to see you or your name anywhere but on the child support checks.
Example 2:
Girl flirts with you on dance floor.
You dance with her.
You bring her back home.
Do stuff.
Next thing you know her BF is at the door wanting to kill you.
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.