My Sister, My Sitter

Lisa enbarks on a career in babysitting, and when Homer and Marge go out for the night, Lisa is left in charge. However, whilst trying to catch Bart and make him go to bed, she knocks down the stairs and he dislocates his arm. He then knocks himself out, and Lisa must get him to Homer and Marge. It is also found out that Bart is 2 year and 38 days older than Lisa.