lunafish prompted me with Blaise/Draco: Animagus, solstice, astronomy.
A Direct Line (PG-13; Blaise/Draco; 200 words)
"The winter solstice is the longest night of the year. Want to put it to good use?"
"Draco, worst line ever. Do better."
"Your turn," Draco snapped, scowling.
"Well, along astrono—er, nomical, uh—hells!" Blaise set Bottle-One-Too-Many down. "A-stron-o-my, yes. Good. Along those lines," he continued, very carefully, "what about, 'Your eyes shine like stars, but I could make them blaze like the sun'?"
"I can't decide: are you pissed, or are you punning?" Draco replied, giggling. Sound like a girl, he thought, shutting his mouth abruptly.
"Don't like it?"
"No," said Draco. "Mother said that Father went the Animagus route."
"Your mother told you that?"
"Well, not directly, but I overheard. Father said something to the effect that his cock was really a cobra. . . . Oh. Oh, why did I 'member that?"
Blaise shook his head. "Doesn't matter, really. I'm too drunk to fuck anyone prop-er-ly."
"Oh." That's disappointing.
"Whash wrong?" asked Blaise.
"You sure? 'Cause I know a charm," Draco replied.
"Les, er, let's have it, then."
Concentrating, quite hard, Draco cast it, first on Blaise, and then on himself. "It worked!"
Blinking, Blaise said, "Astronomy." He grinned. "Yes, I believe it did. Want to fuck?"
"Thought you'd never ask."