Spoilers through 4.08 - Thanksgiving

Brittany was always the glue that held them together. Quinn always had to win and Santana always had to be on top, so everything inevitably spiraled into some sort of twisted competition with Brittany on the sidelines trying to play the peacemaker.

It worked, too.

One touch from Brittany's calming hand and Santana could literally feel the fight drain out of her. Quinn fared no better as no one was exempt from the power of Brittany's pout. By the time the trio had hit sophomore year it was pretty much just part of the circle of life; Quinn would taunt, Santana would lash back, and Brittany would bring the forces of chaos back into balance.

(Brittany for whatever reason would always recite the old spelling mnemonic of 'friends 'til the end.' Santana only thought it was apropos because Quinn and her definitely would be the end of each other.)

That sense of competition certainly didn't die out after high school either. Santana may live almost a thousand miles away from Quinn now, but the distance never smothered the spark that always ignited between them when they were in the same place for more than a few minutes at a time.

And if Quinn was going to mentor that rage inducing little clone then Santana was going to mentor her charge even better.

She was going to mentor the shit out of that street urchin.

Plus everyone knows that Rachel Berry might have given Santana migraines on a daily basis, but her talent always wiped the floor with Fabray. This 'New Rachel' would do just the same with Quinn 2.0.

Then, after Marley killed it at Sectionals and Quinn's little shadow was shamed into the ground, Santana could rightfully take her place at the top of the metaphorical pyramid and shove it in Fabray's face just how much she needs to get her shit together to even hope to compete on the same level as herself.

At least that was what Santana thought as her head whipped to the side with the force of Quinn's slap.

The thunder of her own slap ricocheted through the choir room instantly.

"What are you guys doing?" the familiar voice called out into the room, sinking like a sedative into Santana's veins.

"Nothing," Quinn replied with that damn shit eating grin. "Nothing at all."

The click of Quinn's heels faded into the hallway leaving the uncomfortable curtain of silence that was so common this past month whenever Brittany was left alone with Santana.

"Quinn always was a genius slapper," Santana said quietly before turning to face the other important blonde in her life. "But she is crashing and burning all over again and you should have sat this one out for once. Maybe if we had been alone longer I could have slapped some sense into her."

Brittany cocked an eyebrow at her ex before spinning gracefully on her heel and trailing out of the room in the direction Quinn had just disappeared.

"Or maybe she could have slapped some into you," her voiced echoed back from the hallway.