Disclaimer: I don't own Harry Potter or any of its contents, and I'm not making any money off this.
A/N: This isn't properly British.
She takes the old, tattered text from his long fingers, with barely-veiled disappointment in her eyes.
"You promised it on time," she says. She tries to make it a whisper, not a hiss. Not with him.
If she's cold to him, he'll be cold to her, and Irma can't go back to that. It's too many years, too many months, too many minutes spent chipping away at it all, and he still defies something this fundamental. Books are all she has. She clutches it to her chest in his absence, and Severus grumbles (not unkindly), "I'm sorry."
Because he doesn't say sorry often, Irma lets it slide. She lets too much slide with him. He's the only person who can do this—be late with her things. She's a strict woman; her possessions are golden. Severus is the same way; he should know. They should have an understanding.
He's a smart man, and she thinks he knows her feelings, and maybe that's why he thinks he can break all the rules. He grabs the black sleeve of her robes as she turns back to her office, hidden from students by the walls of paper.
Severus takes a breath before promising, slowly, "I'll make it up to you." Like he promised to bring the book back on time, like everyone does.
But then he leans in and pecks her cheek. And she's too old to need anything else, too mature to need tongue, too immature not to want it. He turns to sweep away, robes billowing.
"Severus," Irma calls, when he's nearly around the corner. He pauses but doesn't look back. He's missing her stifled smile. "If you're ever late with one of my books again, I'll want a lot more than that."