S is for Sacher-Masoch

“I did it!” Harry blurted out, amazed, “I protected my mind!”
“That was just warming up, Mr Potter.” Snape retorted contemptuously. “I shall now attempt to penetrate your mind… while penetrating your body.”
“But… but that’s not fair!” Harry protested, “How could I possibly -?!”
“That is the ultimate test.” Snape replied calmly, “If you pass it, you may stand a chance against the dark lord himself.”
Harry swallowed hard, feeling what little concentration he had been able to muster up to avert the teacher’s attacks shatter.
“Well?” Snape raised an eyebrow and Harry obediently stood up from his chair and went over to the desk to bend over it.
Snape ripped off his trousers with brutal impatience and entered him immediately. Harry gasped in pain but he would let neither pain nor pleasure throw him off guard. He was determined to prove himself worthy and summoned strength he didn’t know he had left to defend his mind against his hard tutor. He could feel Snape thrusting against the walls of his mind with every thrust of his cock, and finally they burst and he couldn’t care less which dark secrets he spilled for the immense pleasure of being fucked by his teacher. A pleasure which did, however, abruptly come to an end.
“Useless!” Snape spat out, “You’re pathetic. A true Potter, slave to your filthy desires.”
“Oh yeah, what about yourself?” Harry retaliated desperately, “You couldn’t keep your hands off my father and now you can’t keep your hands off me!”
“I am not a slave.” Snape answered coolly, “I let your father go and create his perfect little family, remember?”
“And now you’re fucking his son!” Harry shouted furiously.
He felt Snape’s hand tug hard at his hair and force him to look the teacher in the eye.
“I may be, as you put it, fucking you, Potter. However, I am not fucked by you.” he remarked with emphasis on every word.
Harry didn’t know how to reply to that.
“Now, if you don’t mind, I suggest we continue the lesson.” It wasn’t a question, “Prepare yourself.”
The double penetration continued, and no matter how hard Harry tried to defend the integrity of his mind, he always reached a point where the pleasure made him forget himself and the teacher burst through.
“It’s all me in there, isn’t it? Pathetic.” Snape’s voice was dripping with contempt and Harry felt his cheeks turn scarlet.
The humiliation increased his determination to resist the teacher’s attacks. Not just resist – retaliate. He wanted – needed – to know whether he was in Snape’s mind too. When Snape renewed his attack he fought back valiantly and their minds remained closed to one another. Finally, a sigh slipped past Snape’s lips and Harry attempted to take advantage of the momentarily breach in his defence for a doubled attack. To no avail. His teacher’s mind was a fortress, even at the moment of climax. Utterly spent, Harry dropped his defences and let his mind be freely invaded as he too climaxed.
“Since you are not making any progress whatsoever, I think that’s enough for now.” Snape said coolly as he buttoned his pants.
Harry nodded and hesitated, hoping for lessons of a different kind to commence.
“Well, what are you waiting for?” Snape raised his eyebrow, “Do I have to repeat myself: The lesson is over.”
“But –“ Harry begun.
Snape’s only answer was to raise his eyebrow a touch further, motionlessly awaiting an explanation.
“Nothing!” Harry said and stormed out of the room, slamming the door behind him.