When you are having sex with a girl doggy style and promptly punch her anus with a ring pop whilst still having sex.
"Yea I really caught my girlfriend by surprise last night after the movies. I hit her with a green lantern and she had no idea what to do" aka The Green Lantern
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.