Oh, christ, this is the funniest thing I've read in a long time! I cracked up, with my hand over my mouth, for almost the entire thing.
She glanced over at the prick bobbing next to Remus’s head again, this time more clinically, her brows drawn together. "Hang on. Is that Sirius?” she asked. Almost wet m'self here!
and... of course...
“Wait just a fucking minute,” he murmured. Alice froze in mid-suck, then released Sirius’s prick and sat back on her heels. “That is Alice Tumwater’s magic tongue, or I’m Snivellus bloody Snape.” Oh, Sirius!!!