There was a class discussion in science one day, and me trying to be the class clown, called someone a dildo, when I actually meant, Dodo.  None of my classmates caught it.  Well, I think no one caught it because there was no laughter, but maybe it was just the shock and awe of that word coming out of mouth so loud that everyone feared to react.  However, the teacher did catch it and handled it with pure class.  Sometime after the discussion she asked if we could talk outside and asked if I knew what a dildo was, and then in the most professional way you can describe such an object to a high school teen, she did.