Why supervision is important, by Molly Weasley

When Molly Weasley arranges for her 6 year old twins to get to know the nice well-behaved muggle boy in the village, she hopes he will have a good influence on them. In hindsight, she should have been a little more concerned about their influences on him. But it could have been worse. She was sure it could have been worse. After all, no-one had needed to be obliviated.