Baby Shower
Put in charge of organizing my friend's baby shower, I decided to send out invitations via email. To let my husband know that he had baby-sitting duty that day, I entered his name on the "copy to" line.
Within minutes of sending the messages, I received an email back from my husband. He wrote, "Imagine my disappointment when I realized that your invitation wasn't sent only to me."
He was referring to the "Subject" line of my message, which read, "Lunch and a shower."