A/N: I don't know much about the British education system, but alas, I hear they don't have graduation ceremonies - but for the sake of this story, humour me and imagine Hogwarts does.
The applause dies and it's just Severus and Lily, exiting stage right as Professor McGonagall takes the podium, her voice radiating over ten thousand turned heads. "These seven years," McGonagall is saying. "…memories that time, nor…"
They're behind the first sky-scraping House banner, deep blue ghosting their faces when Lily snags his eye, her pace – impossibly quick in deathtrap heels – ebbing slightly.
"Congratulations," her tone is casual, soft beneath the professor's swollen words as she gestures to the gilded plaque in her hands. Lily, fiery hair appearing jarringly red against her cap and gown (rich crimson with gold embellishments), lets her eyes play over her companion's face – oddly pale in the filtered sunlight, oily and achingly tired.
"Likewise," Severus tries to murmur with the same, offhand tone, the plaque's twin – Outstanding Performance in Potions – light in his bony fingers.
"I will never forget," McGonagall exhales a short, rehearsed laugh. "…the time our headmaster…"
Severus realizes he hasn't been this close to Evans to over two years. They seem to have stopped, on pause behind Hufflepuff's airy tapestry. He suddenly wishes he'd slept more, knew a clever quip about the sheer pomp of it all…
"James proposed to me," Lily says quickly, and her eyes – jade and moss galaxies detonating in on themselves – are dead-locked on Severus. He makes a small noise in his throat.
"And?" Severus says dryly, sardonic, a venomous bitter seeping into his voice.
She gives him a look but otherwise ignores it.
"I told him I wasn't ready yet."
Jealous, feigned indifference is replaced by a long forgotten feeling of glee, and he can't help himself:
A thin sneer warps itself across Snape's face.
"Why don't you just go through with it and dump the twit? You never pretended to fancy him before." Hurt snaps into Lily's features, unconcealed and mixing with dampened rage, and for a moment Severus is deathly afraid she's about to hex him – or at the least smack him a good one. Instead she stays where she is, mutely volatile –
"He's changed, Severus," and the girl (Mudblood) doesn't need a bloody wand, her glare piercing ten thousand needles through his raging ego, "I'm sorry I can't say the same thing about you."
And then she's gone, heels cracking languidly against the floor; it's just Severus, Snivellus alone, staring at her receding form…"So as you depart from Hogswarts, the place many of you have come to call your second, even first home…"
"Lily!"
Fuck. She walks on, and he's not going to say, scream, speak her name again –
"…we are proud of you…"
Severus grabs her arm and she turns, face flushed, another dagger swelling, ready to burst from her lips.
"I've always loved you."
Lily is speechless, her lips still daggers but something entirely strange swimming through her eyes. Twenty thousand hands crackle into applause, static-ing past the two teenagers like fog.
"I'm…" she hesitates, and her face softens, and for a moment she's warm sand and summer afternoons. "I'm sorry."
Severus lets her arm go and she looks at him one more time before walking off stage.