A/N- My first Severus/Lily fic! Enjoy!
Disclaimer: I'm sorry to say that I do not own Harry Potter. It would be very unpopular if I did.
Lily stared curiously at her friend, watching his dark hair gleam in the sunshine. Severus caught sight of her and looked up, covering his eyes to fight the sun's rays. "What?"
"Do you wash your hair, Sev?" Lily asked, picking up a strand off his shoulder and rubbing it between her pale fingers. His jaw dropped and he glared at her. "Oh, I don't mean it rudely," she replied, releasing his oily locks and wiping her fingers off on the end of her blouse. "It's just... so greasy!"
Severus sighed. "It's always been like that, nothing I can do." The Slytherin brushed it out of his face and sighed, returning his gaze to the Charms book in his lap.
Lily furrowed her brow. "I'm sure there's something to fix it," she muttered. A thought crossed the girl's mind, and she shut the book in Severus' lap and pulled him off the ground before he could protest.
Lily used her surprising strength to drag Severus into the castle. "Where are you taking me?" he asked with exasperation.
"The dungeons. I have an idea." They ran through the castle, Severus stumbling slightly over the shock of Lily holding his hand. In no time they had reached the damp dungeons, and Severus was enveloped in the cold air he knew and loved. Lily knocked on one of the dark doors, and they heard a call from within as the door swung magically open.
"Why, hello there, Miss Evans!" Professor Slughorn gave the Gryffindor a kind smile as usual. "And hello to you as well, Severus. What can I do for you two?"
Slughorn shuffled his large frame out from behind his desk as Lily spoke. "I was just wondering, Professor, if you know of any good hair potions."
Slughorn laughed and gave his thinning hair a gentle swipe. "Not off the top of my head, my dear. But I don't quite understand, you're hair is-" He paused as Lily coughed and pointed at Severus from behind his back. "Oh. Right. Well then, you're free to experiment to your hearts' content, children. I'm sure two bright young potions students such as yourselves can come up with something mildly useful." Lily thanked the man and dragged her friend through one of the adjoined doors leading to their potions classroom. She pulled out a spare cauldron and set it in from of Severus before ransacking various shelves and drawers.
"What are you looking for, Lily?" Severus asked, partly from curiosity but mostly from worry. Lily was a good Potions student, but if this potion burned all his hair off or something-
"Sev, stop glaring at me. This is for your own good." The ginger girl dumped a handful of ingredients out next to the cauldron and set to work, skillfully chopping and crushing the items before adding them to her steaming brew.
"Wait! Don't add banesberry, that's poisonous!" Severus attempted to swat Lily's hand away, but she tossed the little white berries in the mix nonetheless.
"Don't get your knickers in a twist, that was boom berry not banesberry." She continued to drop in random ingredients, all the while promising Severus that everything would turn out alright. Chopped dandelion root, goosegrass, Nux Myristica, and honeywater were added in rapid succession. Lily snickered and pretended to add lovage, an ingredient in most befuddlement draughts, but Sev glared at her and made her drop it. "Okay, I think it's almost done." She added a bit of mint leaf ("Well it should at least smell nice after this!") and one long peacock feather to the potion before taking a deep breath and stirring counterclockwise twenty times. The brew turned a strange shade of purple, then settled on a soft lavender color.
"We should probably test that on something first," Severus said cautiously. "I don't want all my hair to fall out."
"Right, right," Lily replied absentmindedly, glancing around the room for a test subject. Sadly, everything in the dungeon was in a jar, dead as a doornail. "I'll be right back," she mumbled, running as quickly as possible from the room. Severus waited and stared at the mixture with weary eyes, wondering what it was going to do to him. Lily soon returned though, interrupting his thoughts when she threw a rat into his arms.
"You ran all the way to the Transfiguration room for a rat?" He held up the rodent and watched as its beady eyes glanced around with worry. It was shaking with fear and attempted to bite Severus, so he held it out of reach.
"Well that's where I was headed, but I ran into Sirius on the way and he was more than happy to loan me his. Said the Transfiguration room was too far of a walk, and he didn't mind as long as I didn't blow the little guy up." She scratched the rat between the ears as he continued to squeak and fight against Sev's grip. Lily made a disgusted face and wiped her finger off on her blouse again. "He's the perfect test subject too, the state of his fur is much worse than your hair." Lily took a dropper off the table next to them and filled it with some of her mixture. She put three droplets on the rodent's back, and they watched as his fur began to glow.
"Lily, I don't know if-" Severus cut himself off with a gasp as the glowing abruptly stopped, leaving soft, fluffy fur in its wake. Lily smirked and gave Severus a wink.
"So, let's bottle some of this up," she said, taking the rat from Severus and dropping him on the floor. He scurried out the door, and Severus swore he could hear frantic footsteps not long after the rat had left their sight. Lily paid no attention and instead began to trap her concoction in a series of large flasks. She ran her soft hands through Severus' dark hair, and he felt a blush creep into his pale cheeks. "You can use this. I really hope it helps." Lily slipped one of the flasks into her friend's hand and walked out the door.
Severus watched her go, still blushing and clutching the flask like a lifeline. He sincerely hoped it improved the state of his hair, if only that meant Lily would run her hands through it just one more time.
A/N- If you take anything away from this, let it be that Snape and Lily just performed experiments on Wormtail. Also, in my headcanon Snape stops using the potion after Lily becomes closer to James and the Marauders because he has no need to feel clean/attractive anymore. Poor Severus...