The Dog You Feed

When Sirius ran away from home he went to live with the Potters, but before he made it there he wound up lost, alone, and hurt in Muggle London. With James out of the country, Peter stuck at home, and Remus trapped by the full moon, it's Lily Evans, who can hardly stand him, that Sirius is forced to turn to for shelter and more advice than he could have bargained for. Pre-Wolfstar.