Used to refer to a day in which you are having a bad temper or are in a bad mood.
Origin: A person, that shall remain un-named, had a friend spit chocolate on their new pants and got really upset, started yelling and ate her friends. Every time someone is in a bad mood and having a short temper they are known to be in a "chocolate pants mood" or having a "chocolate pants moment"
"Don't talk to me right now, I'm having a chocolate pants day."
"Vives, you're having another chocolate pants moment aren't you?"
Nancy: Smells like someone crapped themselves
Uriah: Yeah no shit. Probably Tom!
Tom: Hell no! its that retard Eric!
Eric: Uh...anyone got a clean set of drawers?
Kevin, Nancy, Uriah and Tom to Eric: Chocolate pants, chocolate pants, can't get a ticket to the retard dance.