it wasn't awful for me personally, but it was for one of the guys in my exam.
he'd clearly finished, and was in a world of his own because he randomly started singing. he went on for ages, totally oblivious. we were all trying not to laugh, the invigilators clearly couldnt believe what was happening cause they spent ages just looking at each other in confusion. when the poor guy realised he was so humilliated. we never let him forget it, which i guess is harsh, but it was one of the funniest things ever.