Practical
"Pay attention, Draco," Snape snaps at me, and I roll my eyes at him because I know how much he hates it.
"Will this be on the final?" I learned this spoiled brat's tone of voice long ago, but it was not so long ago I learned it makes grown men hard. I can see Snape responding already; as tight as his trousers are, there's little to be left to the imagination. But it's me that's in trouble; he's always hated that I can do this to him, even more than he hates not being able to discipline me. Today he no longer has to restrain either of his desires; he pushes me back, hard, against the chalkboard, knowing full well what chalk dust will do to my new robes. Bastard.
"Yes," Snape breathes into my mouth, and I can feel myself smiling with a most un-Malfoy pleasure. He kisses like he's looking for answers to questions I can't even imagine, and I close my eyes so that I can think only of him and of this. Snape says something that might be "Malfoy," or "Fuck," or even "More." I choose to think it was "Draco," but really I have no illusions. He's undone my zipper one-handed, most impressive, and he's about to discover that there's nothing in my trousers but me.
This seems to shock him back to awareness; he pulls away a little, more mentally than physically, and says clinically, "Remember not to rush things too much. It's important that both subjects be aroused and totally comfortable in their surroundings." I wonder whom he thinks he's kidding; I know as well as he does that the aphrodisiac potion we both took was only a nod to the format of the ritual.
There's nothing comfortable about the way he claws at my belt, at the button, the way he rips my trousers down, and tears my robe because he can't work the fastenings. But I do find it arousing, and I suppose this is noticeable. And he did say at the beginning that it is important to proceed in the manner most appropriate for the situation. I keep my eyes closed as he pushes me into position against the desk. It's awkward; fortunately Quidditch has kept me limber, and this way I can imagine we're somewhere more exotic than the Potions classroom.
The finger Snape pushes gently into me is greased with something that burns just the slightest bit, so that I can't help but push back at him. He says something crude about my lack of self-control, even as he slides in a second finger, and a third. I may be a bit of a whore but I am not so vain about my size as him. After his fingers his penis feels small, but he wraps his fingers around me and manages to bring us off together. When we finish the Gryffindors and Slytherins give us a standing ovation; they know class when they see it.