When your wife is sleeping hard and needs to wake up, so you go in for a quickie to jump start her day while attempting to climax right as she wakes up
I'll be a little late to work today, need to take care of a deadbattery
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.