One of my co-workers had a full beard/mustache thing going on. One day, after I'd settled in at my cubicle, I turned to wish him a good morning, and squealed not so very quietly "You're NAKED!" Really, he'd only just shaved everything off, but after months of hair I was quite surprised!
My other little instance also happened at work. I was a CSR, answering phones. It was busy, and as I answered my next call I combined two of our common phrases-May I help you, and Can you please hold for a minute?, and after the appropriate greeting, I proceeded to ask the gentleman on the phone "May I please hold you?" Thankfully he was in good humor and he couldn't see my red face! :oops: