Of Snowflakes and Mulled Wine

Fic for the December prompts for the House of Snarry December Prompts. It's the Slug Club Christmas Party, the first one after the war. Headmaster Snape observes, and Harry wants. And he wants a lot, maybe more than Snape can give him. Or is it?

Fandom: Slug Club Party
Song: "All I Want for Christmas is You" - Mariah Carey
Picture: Snowing in town
https://www.pexels.com/photo/rain-of-snow-in-town-painting-730256/