Too much pedal

Johannes Brahms could be incredibly rude, even to his friends. While playing a Beethoven sonata with a cellist friend one day, he applied his piano’s pedals with more enthusiasm than the friend had hoped. “Softer,” he pleaded, “I can’t hear my cello.” “You are lucky,” Brahms replied. “I can.”

Source: N. Slonimsky, Book of Musical Anecdotes