Last week at work, my coworker was telling me all about this black tie wedding her and her BF were invited to, and how much of a pain it was going to be to get him a tux. I was all "Ooooh, a real black tie wedding, I can't wait to hear all about it!"
Today at work, she told me how much the tux rental set her BF back and she was debating whether or not she should spring for a floor-length dress. She said, "BF's already going to be wearing a tux, and the invite says 'Black Tie Optional,' so I just don't want to be the only super-dressed up couple at the wedding and stand out in a weird way."
I kinda did one of these:

and then we discussed the difference between a true black tie wedding and the one she was attending which is, like pretty much all weddings, black tie optional by default. It's ridiculous that people really think their guests won't know to dress formally for a freakin wedding