Brahms attended a Wagner concert in Vienna:
All through the concert Johannes sat in stony silence. At the close, when everyone was applauding vigorously, he still made no move or comment. Finally his companion – beside himself with enthusiasm – cried: “What music! Wasn’t it marvellous?”Goss, Madeleine & Schauffler, Robert (1943) Brahms The Master. New York: Henry Holt and Company, p.183-184.
The composer raised his eyebrows a little. Then he asked drily, “Aren’t you afraid you will spoil your new kid gloves – clapping so hard?”