Go hog-wild

You're drooling as you approach your professor's huge, bared ass. Your cock is drooling too, in fact it's already spurting; you can feel a massive load stored up in your balls from all her teasing, and your cock is eager to fuck the new pussy and breed it many many many times. You get down on your knees behind her and start rubbing your cock mindlessly between those glorious asscheecks, delighting in the sensation.

"John, I appreciate you're a bit stupid right now, but I don't want you to coat my backside with your pre I want you to FUCK ME." She punctuates her sentence by arching her back even more so her pussy rubs up against your shaft.

Her authoritative tone of voice brooks no disagreement and you find yourself jamming your impossibly thick member into her beautiful, soft pussy. She's incredibly tight, as you guess all women would be for a member that's more than three inches wide, but you still feel practically no resistance sliding into her slippery depths.

She makes not a sound, but shudders and squirts on you when you hit bottom. Dazed, you just revel in the unbeatable sensation of having your whole cock sheathed.

"Don't be shy, boy, use all the energy you've got. I promise, I can take anything you have to give."

Your cock snorts at the challenge, and you feel it attain an incredible level of hardness within her, seeming to surge in size. She gasps and shudders again, almost losing her legs, but your grip on her hips becomes vicelike. You're in a daze as you watch yourself start to pull out your cock in one long, smooth stroke and slam her down on it, fucking her with strength you didn't know you had. Within seconds she's having a nearly continuous orgasm, melting into a puddle on the floor while you hold up her ass and give her the roughest fucking you've ever seen.

You feel like you're right on the edge of orgasm, but your cock isn't satisfied with just pumping this one full again and again. It wants to show this pussy what it can really do. Your arms grab her unbidden and pull her upright by the shoulders, then grab one of her huge tits. Your hips never stop during this whole maneuver, and as you thrust you feel her pussy getting tighter and your balls getting heavier, until with some shock you realize they're actually touching the ground. Your cock, and indeed the rest of your body, doesn't miss a beat though, continuing to obliterate your teacher with wild abandon. You're not in control, but you're not even trying to be; the pleasure is so much and you did after all decide that you were going to fuck her.

She's whimpering and quivering this whole time, and your cock is satisfied that you've finally broken this bitch, but when you feel the familiar surge of cum it stops at a vicelike grip inside her pussy.

"Oh, thought you were going to beat me that easy, huh?" Growls Professor Pifflewhiz through gritted teeth, seemingly at your cock rather than you. The pressure in your balls and the tightness of her pussy reach unbearable levels. She starts rhythmically milking the head of your cock with her demonically altered mega-pussy, and chuckles.

"I've been around for hundreds of years, you stupid animal. I've had incubi begging me to let them stop. You think I'll let you off that easy?" She starts sliding her body up and down, fucking her solid slabs of muscle along the log inside her. Your cock, still trying to come, surges in size again and mounts even more pressure behind the titanic orgasm, though it feels like it's at the limits of its power. You watch with disgust and fascination as it gets nearly as thick as your (admittedly skinny) thigh. Still, it's not enough to overcome her impressive, and probably magical, vaginal strength.

"We're gonna be here for a long, long time, you'd best conserve your energy John."

The demon seems to hesitate and stops possessing your body, and you find yourself just standing there on your knees, teetering right on the edge of orgasm, while your professer fucks herself on your absurdly huge cock. All you can do is watch that muscular back and that huge bubble butt slam down on you wetly, again and again, until she decides it's time to switch it up, literally picking you up with your cock still firmly embedded inside of her and putting you on the ground, this time fucking you while facing you. Your balls continue to swell as the demon keeps trying to cum, reaching grotesquely huge sizes. Your vision goes red while you watch her perfect, huge breasts bounce hypnotically above you for some length of time you can't determine, until she decides to switch it up again. And again. Alternating between riding you and goading you to fuck her with all your might. You're literally foaming at the mouth by the time she finally, mercifully, allows you to cum. The pressure in your loins is lifted and you briefly feel pleasure inconceivable before you pass out.