"Ron! It's moving!"
"What's moving?"
"The green stuff in the pot! Where's my wand?" Hermoine frantically glanced back and forth.
"I'll give you a Sickle to eat it!"
"What? No!"
Sirius entered the kitchen when he heard a metallic clamor. Hermoine was levitating a pot, and ramming it into Ron's cranium.
"Aren't you two supposed to be cleaning?"
The pot hovered momentarily in mid-air before plunging to the floor. The teenagers looked liked they'd been caught with hands in the proverbial Bottie Bert's Every Flavored Beans jar.
He dismissed it with a wave of the hand, and the pot skidded across the room. "Oh, I didn't mean to do that…but it doesn't matter. I have something that I need to talk to two about."
Both Ron and Hermoine grew wary, remembering countless other objects that had become dented, rusted, and lost in their supposed-to-be-cleaning hands.
"It's nothing bad," Sirius assured them. "But… maybe we should be somewhere more private… where we can sit."
The students followed Sirius into a sitting room, Ron fleetingly wondering if prison had done bad things to Sirius. Ron and Hermoine sat together on a couch and Sirius took an armchair opposite them, looking rather grim.
"Now, I know that, with everything going on, you two have spent a good deal of time together… unsupervised."
"We've been working really hard! …Most of the time," Hermoine protested.
"Oh, I don't doubt that!" Sirius comforted them. "No, it's not that at all… not at all…" he began looking slightly preoccupied. "Well, I've been told by George that, after the fifth time, your mother got tired of giving the talk," he directed at Ron. Turning to Hermoine, he continued, "And… well, you being Muggle-born and all, I'm not sure how well Muggles understand it themselves."
"What 'talk'?" Ron asked dimly.
Sirius sighed heavily before continuing. "Do you two know anything about… the Goblins and the Unicorns?"
"What are you getting at?" Hermoine asked confusedly.
Sirius's voice became slow and monotonic. "Sexual relations."
"Sexual relations?"
"Sexual relations. You see, when a wizard and a witch… or sometimes two wizards… and on occasion two witches… well, when two people love each other very much… or when they've drunken too many Butterbeers… or when they just want to fit in… or when one is pressuring the other and one doesn't want to lose their date to Hogsmeade… they disrobe and—"
"Whoa, Sirius! We've had this class in Hogwarts already!" Hermoine interrupted, flustered (Ron was too busy being fascinated by the number of ways a wizard and witch, two wizards, or two witches could come to engage in sexual relations).
"Oh, have you?"
"It's mandatory in the second year."
"Well, that sure would have saved me a lot of trouble if they'd had that when I was there… who teaches it?"
"Professor Binns."
"Oh, I wouldn't have learned anything anyways."
"Yah," Ron agreed. "I had to borrow Hermoine's notes for the test."
"Yes, well, if you need to know anything more specific… or interesting… or if you need certain… items… I'm not sure what the Muggles have," he addressed Hermoine, "but in the wizarding world there are some potions one can easily obtain… if you need anything for when you're unsupervised, you can just come talk to your friend Sirius."
Sirius, looking proud of himself, stood, gave them both a bolstering pat on the shoulder, and exited the room. Hermoine and Ron sat in complete silence for quite a while, trying not to think about what had just been implied (and also avoiding thoughts of Sirius having sexual relations) before Hermoine turned to Ron.
"I'll give you a Sickle to ask for a 'sexual relations' potion."
"You're on."