a life of smoke and silvered glass (смешанная)

Albus Dumbledore rose to his feet, smiling at them in that way of his, like he knew something you didn't and he was proud of you for it. "Friends," he began.
The door thudded open and the Marauders burst in, late and pink-cheeked with cold. The headmaster smiled at them, too, and Sirius gave a cheery little salute back.
Severus sunk lower in his chair, staring witheringly over his butterbeer. "You told Potter about it, too?"
"He might as well put all that energy to good use," said Lily. "And, to be accurate, I told Remus."
"But Potter, really?" said Severus.
"He and Black cooked up a jinx that gives you a boil every time you say a slur to a Muggleborn," said Lily. "It was either invite them to Alice's war club or bake them cookies, and I know where my skills lie."
Severus sniffed. "Don't come crying to me if he tugs your pigtails."
"Come crying to me if he pulls yours, and I'll deck him," said Lily.
(Slight AU in which Severus apologizes, tries harder, and stays friends with Lily)