Lily was walking through Diagon Alley shopping for potion ingredients when she saw him. The potion master. Her favorite mistake, her guilty pleasure.
The muggles would refer to him as her 'friend with benefits', a 'bedmate' or a 'bedpal'.
Ever since her seventh year of Hogwarts when she'd first fallen for the charms of Severus Snape, her friend since childhood, he'd been her weakness. She always promised herself afterward that it was the last time. She'd avoid him for a few days. Then she'd make eye contact with him, he'd raise an eyebrow and her resolve would break. They'd end up hidden in some corner as his kisses burned her skin and she sank her nails into his back. She had a boyfriend, and Severus knew this, but the affair continued.
She'd married fellow Gryffindor James Potter a few months ago, after they'd dated for 2 years. He was a hard worker. Predictable and steady. But did she love him? She tried to convince herself so, but she'd dreamt of Severus so many times that she'd lost count.
Their marriage had been pushed by his family and by her fellow Gryffindors. Severus had stood on the outskirts watching intensely as they'd said their vows. She made eye contact with him as she and James were pronounced husband and wife.
Now she was face to face with the Potion Master in front of Olivander's wand shop. James had gone to the Quidditch World Cup with Sirius and Remus, and wouldn't be back for two days.
She stared into Severus' eyes and got lost in their dark depths.
"Hello, Lily."
"Hello, Severus."
"Are you here with James?"
Lily shook her head. "He's at the World Cup. He won't be back for 2 days."
The dark eyes stared intensely at her as the eyebrow went up. "Two days, you say?"
Lily felt herself flush as she looked around. No one else was nearby to witness the two of them talking. Or leaving.
Severus offered his arm out to her and they apparated to his house in Spinner's End.
Some time later, a trail of clothes led to his bed where two flushed, sweaty lovers lay tangled on the bed catching their breath.
Severus brushed Lily's hair from her face. "Don't go back to him. Stay here with me."
Lily sighed. No one in the world made her feel like he did. In her most intense moments, he'd raise that eyebrow. That's why it was such a weakness to her.
But she was married now.
"I can't."
"We could spend every night together like this. No more sneaking around, no more hidden corners."
"Severus…."
"I love you, Lily."
"I love you too, Severus. But, I can't."
In one quick move, she pushed her lover onto his back and straddled him. "But you've got me tonight. And tomorrow night."
She watched as he smirked and called out the name of a potion and a small vial flew to his hand. He quickly downed all of it and sent the vial back.
"What's that?"
"A stamina potion I created. I'm going to keep you up all night long."
Severus grabbed his wand from the bedside table and waved it at her.
"Statim gaudens."
Lily's face flushed and her eyes rolled back in her head as she threw her head back as his mumbled words pushed her over the edge. She let out a load moan, and his arms steadied her until her breathing slowed and she opened her eyes.
"Remember the first time I tried that spell on you after I invented it, Love?"
She smiled and blushed at the memory. Everyone else was at a Quidditch match, but the two of them had snuck up to the Astronomy tower. They had snogged on the floor until he smirked and pulled out his wand. He had mumbled the words in her ear, then raised an eyebrow and watched with aroused fascination as she came apart. Then he did it again, and she came even more intensely the second time, gasping his name and digging her nails into his shoulders.
Unable to hold himself back, he'd quickly removed both of their clothes magically and thrust into her. They were far enough from the pitch that no one heard their moans or the near scream Lily let out as she came a third time, grabbing the Slytherin's black locks.
Now here she was, straddling his waist, still panting from her magical orgasm. He raised his wand again, but she stopped him.
"No, Severus. I want you inside me. Now." She raised up and pushed herself over him. He watched as her breasts bounced with every movement she made as his hands firmly grabbed her buttocks. After a few moments, he flipped them both over.
After, she curled up against his chest and fell asleep. He held her and watched her even breathing and contemplated running away together.
When she woke up a couple hours later, the two lovers had quickly resumed their passionate marathon. The potion he had ingested earlier enabled them to partake of each other as much as they desired. The air may have been cool outside, but inside the little Cokeworth home a fire burned, fueled by their long contained passions.