Reading the books- Marauders era

What's Malfoy's house elf doing in their room?

"Oh - really?" said Harry, locking eyes with Hermione then looking back at Dobby. "Er - I don't want to be rude or anything, but - this isn't a great time for us to have a house-elf in our bedroom."

"Oh it can be," James said suddenly, his eyes bright. "You can ask him to apparate you two out of this house along with your stuff and call for a Knight Bus telling them to leave you at the Weasley's home or to the Leaky Cauldron."

"They don't know that Dobby could apparate them, James," Fleamont reminded him. "And even if they did and somehow he apparated them out of the house, they wouldn't know how to call for a Knight Bus, would they? Merlin knows if they are even aware of its existence!" He exclaimed.

Aunt Petunia's high, false laugh sounded from the living room. The elf hung his head.

"Not that we're not pleased to meet you," said Hermione quickly,

"Say that after you know why he's here," Marlene advised.

"but, er, is there any particular reason you are here?"

"Oh, yes, miss," said Dobby earnestly. "Dobby has come to tell you, mis ... it is difficult, miss... Dobby wonders where to begin . . . ."

"From the start," Regulus suggested.

"Sit down," said Harry politely, pointing at the bed. To his horror, the elf burst into tears - very noisy tears.

"They are going to die on their twelfth birthday," Remus said.

"What did I do now?" Harry groaned.

"Nothing, Harry," Euphemia sighed. "You did nothing,"

"For the first time, Harry," Hermione shook her head, looking at Dobby, "I don't know what did you do wrong."

"S-sit down!" Dobby wailed. "Never ... never ever. . . "

"We can see how greatly you take care of your elves, Mrs Malfoy," Lily said, her lips curling up in disdain.

Narcissa didn't reply and instead, furrowed her brows, thinking of a reason why Dobby would be mistreated in future.

The twins  thought they heard the voices downstairs falter.

"I'm sorry," Harry whispered hastily, "I didn't mean to offend you or anything -"

"You didn't offend him, Potter," Barty said.

"Offend Dobby!" choked the elf. "Dobby has never been asked to sit down by a wizard - like an equal-"

Hermione, trying to say "Shh!" and look comforting at the same time, ushered Dobby back onto her bed where he sat hiccoughing, looking like a large and very ugly doll. At last he managed to control himself, and sat with his great eyes fixed on Harry and Hermione in an expression of watery adoration.

"Great," Severus muttered disdainfully, "even house-elves are a part of the Potter fan club."

"My children are just being kind to him, Severus," Lily snapped, hey eyes narrowed. "Unlike some other 'highly bred' wizards." She scoffed.

"You can't have met many decent wizards," said Hermione, trying to cheer him up.

"True," Sirius snorted, making Lucius glare at him.

"We are way more decent than you, Black," he spat.

"We can see," Mary snorted. "Decent wizards and witches treat everyone as their equal, Malfoy; they don't look down on anyone." She met his eyes, challenging him to say anything to her.