Today, it was the other way for me.
I was halfway through ordering some chips when a mobile phone rings. The guy serving me took the phone out of his pocket, answers it and was all "OH HAY MATE WASSUP".
I was so flabbergasted that I just left.
Just to make it a bit clearer. One, this guy isn't the manager (I've talked to the manager a few times, nice guy), and two, it's not the company phone. It was a mobile phone with an interchangable covers, so obviously his.