Harry's curious about his parents, and Sirius can't blame him. There's so much he'll never get to know, even with all the stories Sirius and Remus can tell him about them. They have a lot of stories about James, and they tell some of them while they're cleaning out Grimmauld Place.
These previously redacted sections of Mrs. Emerson's journals have been published not for the purpose of prurient gossip, but to provide a fuller picture of the early days of the Emersons' partnership. A coda to "The Crocodile on the Sandbank."