The rivalry between the Barden Bellas and the Barden Treblemakers was basically sacred at Barden University.

And if there was one person who took that rivalry more seriously than anyone else, it was Aubrey Posen.

Aubrey was the definition of discipline: perfectly curled blonde hair, posture straight like a ruler, pearl earrings, red lipstick that never smudged. As the leader of the Bellas, she enforced every rule with military-level seriousness. The biggest rule of all?

No sexual or romantic involvement with Treblemakers. Ever.

The Bellas even jokingly called it “The Bella Oath.” 
Aubrey was the one who wrote it.

So when the Treblemakers introduced their newest member, nobody expected Aubrey to even notice him.

He wasn’t loud like the others.
He didn’t flirt with every Bella he saw.
He didn’t act like he owned the stage.

Instead, he stood slightly behind the others during rehearsals, quiet but confident. When he sang, though… everything changed.

His voice was smooth, controlled, ridiculously talented. The kind of voice that made people stop talking mid-sentence. The first time Aubrey heard him sing during a rehearsal in the auditorium, she froze.

Not because she liked it.

Because she felt something.

Something she definitely wasn’t supposed to feel.

For days she tried to ignore it. She focused on rehearsals, choreography, vocal drills. She corrected Chloe’s breathing technique, criticized Fat Amy’s timing, and repeated the oath to the Bellas like a prayer. But the problem?

Every time the Bellas rehearsed in the auditorium… 
the Treblemakers rehearsed next door. And every time Aubrey heard his voice through the wall, her concentration completely shattered.

It got worse the first time they actually spoke.

He wasn’t cocky like the other Trebles.
He was polite. Soft-spoken. Almost shy. “Hey… uh, good rehearsal,” he said one afternoon, giving a small smile as they crossed paths backstage.

Aubrey blinked, surprised.

“…Thank you,” she replied stiffly, adjusting her Bella scarf like armor.

That should’ve been the end of it.

But it wasn’t.

Because suddenly Aubrey Posen — the girl who wrote the rule — found herself thinking about the one person she absolutely wasn't supposed to like.

And the worst part?

She had a feeling he might like her too.