Lancelot played a prank on his father old Gobbo who was half blind and cannot see clearly. By asking directions of the house of Shylock. He does that intentionally because he was happy to see his father after a long time. His appearance was changed so his father could not identify him and hence gave him bad directions to Shylock's house. It was after this that he told his father that his son was dead. On hearing this, his father became very sad which was apparent from his facial expressions. He later told his father the truth and apologised to him and kneeled before him.