This was written in response to a prompt I got on tumblr from anon!
When the hat got placed on Barry's head, it dithered.
You've got quite the thirst for knowledge, Mr. Allen, though it seems to be directed towards specific topics I see. A brain like yours could certainly thrive in Ravenclaw but there's a fire in you, a great courage in you that could only be nurtured in…
While Barry wouldn't have minded Ravenclaw, the nice-red-headed girl he'd met on the train was convinced she'd be put there, Barry was proud to be in the same house as his father. Even Cisco, the other boy he'd met on the train, getting put into Ravenclaw didn't dampen his excitement, especially not when his foster sister Iris was made a lion as well. However, there was one boy who'd stood out to Barry during the sorting, and for all the wrong reasons. Barry was certain he had seen Leonard Snart pick-pocketing on the platform and as the hat sorted him into Slytherin, Barry vowed to keep an eye on him.
Barry hadn't intended to form a rival with Leonard Snart that day but it quickly became necessary. He had always prided himself on his potions skills and he refused to be beaten by the boy who pick-pocketed on the platform, who had definitely been helping Slytherin cheat during the last Quidditch match and, worst of all, threw ingredients into the cauldron with an uncaring attitude and still ended up with perfect potions.
By the end of Christmas their scores in potions were tied for top spot and while Cisco and Caitlin tried to reassure him with the reminder that they still had the rest of the school year to go, it still frustrated Barry. He'd debated going to the Professor about his suspicions that Len was cheating (he had to be, he wasn't even looking at half the stuff he chucked in there!) but considering the man had taken points from Gryffindor just because he sneezed, he recognised that there wouldn't be much point.
No, this required him going to the source himself, though, he did make sure to wait until Len was alone. Just because Barry was a Gryffindor didn't mean he was suicidal. He intended to confront Len in a mature fashion but keeping his cool became a lot harder when Len just laughed at Barry's calmly stated accusations.
"What can I say, some people are just gifted," Leonard replied, an infuriating smirk on his face.
"You don't even seem to care about the potion! You have to be cheating somehow," Barry argued angrily, a breath away from stomping his foot.
Leaning back against the wall, Len folded his arms. "Wanna bet on it? A competition to make one potion. Just you and me and no books allowed. It can be a potion we've done in class, like the cure for boils. Whoever makes it best, or in the quickest time, wins. Deal?"
Thoughts of being caught breaking school rules didn't even cross Barry's mind as he growled out, "Deal. When and where?"
"There's a room on the seventh floor. It only appears when you desperately want something. It should have everything we need. We can meet there, say, seven pm tomorrow?"
"I'll be there."
Like most things that are supposed to be kept secret tended to do at Hogwarts, the tale of the great potion's competition spread throughout the school, lasting for years to come. During this time, both Barry and Len were made the figureheads of their heads, not helped by the fact that the pair were both made seekers; Barry in their second year, Len in their third. Whereas Barry was the faster of the pair, Len was the master of tricks and distraction and his actions bordered on a fail far too often. Len didn't match Barry in becoming Prefect, however, a new game formed then – would Barry manage to foil Len's latest plot in time? Oh, the plans Len formed were mostly harmless, he'd only been threatened with expulsion a couple of times, but they could be very, very annoying, especially depending on who they were aimed at.
What the majority of students didn't know, however, was that most evening you'd be hard pressed to find Barry or Len. You could scour the whole school but you would never find them and that was because they would be in a secret room, a room that held a special place in their hearts and allowed them all the privacy they wanted.
"You are not kissing me during my speech," said Barry, his eyes rolling but a reluctant, fond grin on his face.
"You always say you want me to be romantic," Len argued playfully. "What was the point of all this secrecy if not for the big reveal?"
Barry raised an eyebrow. "I think you've found plenty to enjoy from it already."
"Well, so have you. I'm pretty sure you wouldn't have this if it weren't for me," Len smirked, flicking Barry's Head Boy badge. "In fact, if it wasn't for me you might not even be here today."
"And if it wasn't for me, neither might you."
The truth of the potion's incident went like this: The pair had started off well, both focused on getting a head start, but it soon dissolved into inevitable bickering. In fact, the pair quickly got into such a heated argument that neither noticed Barry's cauldron turning a dangerous maroon colour. Len noticed just in time to jump in front of Barry and cast a shield charm, something Barry himself had to do when Len's potion also exploded. It turned out that saving each other's lives was a great bonding experience and their embarrassment over what happened meant they agreed no one would know the truth of that evening. And then, because it turned out to be mostly amusing, apart from their close friends, no one knew they actually got along very well. Well enough to begin dating in their third year.
"Okay, you can take that out right now. I am not calling you my snookums in front of the whole school!"
Len sighed dramatically, flicking his wand and removing the beautifully worded sentence. "One would think you don't love me, Barry."
Again, Barry rolled his eyes but his smile softened. "You know I do. Compromise then; at the end, you can set off those fireworks I confiscated from you at the beginning of term."
Len grinned. Unbeknownst to Barry, there'd been a very special reason he'd let his boyfriend confiscate them. Honestly, he'd been happy to wait until after graduation to use them but…it would certainly kill two birds with one stone. Anyway, Barry couldn't be too mad during his own proposal now, could he?
"And this, Barry Allen, is why I love you."