"Don't you ever think of anyone but yourself? You're a fool, Snape. If you can't see it, then you don't deserve it." McGonagall snapped and stormed out of the room I was standing outside of. I dived behind a suit of armour before she noticed me, watching her slight frame march away then I stepped out carefully, and tiptoed gently into the classroom where Snape was now sitting alone, head in his hands. He started as I steadied my nerves and walked towards him boldly, heels clicking on the stone dungeon floor.
"Miss Granger, what are you doing out of bed at this hour?" he said it coldly, but there was a flicker of something I couldn't quite read in his eyes.
"I... I've just started the essay you set earlier and I was wondering of you could explain something to me. You see, the Healer who created this potion also invented another, and I was unsure as to whether or not it is really valuable as a potion on the whole."
"And which potion would that be, Granger?" he said lazily.
"I think you know, sir, considering that these are the only two potions concocted by that particular Healer." It didn't matter how nervous I was, I was trying to be seductive as hell - but he wasn't aware of this at all.

******

Why is she looking at me like that? And why on earth does she want to know about that potion... The Intensifier. It makes sex so amazing that there is a chance of the two people feeling feigned love for each other, but eventually the potion becomes obsolete in the body, and the mind turns to hatred for the person formerly a lover. Ironically, it sends people to madness.

******

I wanted to hear him say it. I needed it. "Sir?" he coughed awkwardly, breaking himself out of his thoughts.
"Well," his eyes stayed on the desk in front of him, "for some people, it can bring a pleasure so intense that the feelings of love are fabricated." his eyes moved to mine and he seemed to decide something. "It can make an orgasm so utterly amazing that people become addicted to it, and it is therefore banned in a lot of places for ethical reasons. Furthermore, I have never met anyone who can brew such a complicated mixture."
I walked to the front if his desk and leaned over a little, smiling.

"But I bet you can, can't you sir?"

His eyes flicked repeatedly to the cleavage on show in front of him and he seemed frozen.

"I have never tried Miss Granger. Nor do I intend to."

There was a pause as we looked at each other, and a cruel smile spread across his face. "Why do you ask? Weasley not good enough for you?"

******
Her face fell a little and I felt a familiar flicker of guilt; I hated having to do this. It would never get easier to see that look on her beautiful face but I had to! She is sixteen. And my student. It's wrong, Severus.

******

"Ron and I have never and will never be together like that, Professor." I stated. "You say you've never tried to make it? Why's that?"
I had had enough. I moved around his desk and sat on it, placing a foot on either side of his chair and closing my knees tightly. He was gazing at me.
"I've never needed it to make someone scream."
He placed his hands on my thighs and let them linger everywhere, moving to behind my knees. He paused, watching he breath enter and leave me, my chest rising and falling. He tugged at my legs until I was suddenly straddling him, feeling a strong hardness against me, and he gasped as I moved against it, the friction pleasuring him. He untied my cloak and as it fell away he became aware of how little I was wearing; a tight vest top with no bra underneath, showing everything, and a short skirt which had previously been covered by the cloak. He pushed the skirt higher, revealing black suspenders joined to lacy underwear.
"Sir..." I gasped.
He looked at me.
We jumped apart as footsteps were heard approaching down the corridor, heading quickly for the open door of his classroom. "Oh shit," he breathed, encouraging me to hide. I dived to the floor and slid under his desk as he threw my cloak in after me and hurriedly picked up a quill in an attempt to look as though he had been grading papers.
"Severus, you are needed urgently in the hospital wing; a fourth year has swallowed your entire Coughing Solution and is currently busting a lung, please could you come?" a voice said, it sounded like a less dreamy Professor Trelawny.
"Of course, just a moment." he answered calmly. The footsteps began again, receding this time. I sighed in relief when he lowered his face to look at me.

"This won't take long, but it would be too suspicious for me to come back to my classroom afterwards, it will be too late. Wait 5 minutes after I leave and then go." He stood up and left me, feeling bereft and still breathless.