I do not own Gravity Falls.

Mentions of alcohol and (accidental) underage drinking.

Prompt: Eggnog

Some Eggnog Isn't For Everyone

Mabel skipped into the kitchen, humming a Christmas melody under her breath and dark green flats tapping against the tiles as she went in search for a drink. She instinctively went for the pitcher of fruit juice before her eyes landed on an unfamiliar jug stuck towards the back of the glass shelf, snuggled between milk that was most definitely expired and Ford's homemade protein smoothies.

The festive red and green colouring caused her to reach in and grab it, pulling it towards her for closer inspection. "Eggnog?" she said with intrigue.

Her parents did not drink eggnog, and so it was never in their household growing up. They also continuously denied her pleas to try some, leaving this one Christmas tradition she never partook in. A slow grin curling across her face, she happily poured herself a glass. The liquid was thicker than she anticipated, but then again she did not know much about eggnog (other than the obvious-it was made with eggs).

She took a curious sniff. "So far so good," she decided. With no further hesitation she took a gulp, her taste buds immediately reacting to the new flavour. "Ooh, it tastes like custard!"

As she continued to guzzle the sweet drink, her brother happened to walk in. His attention locked on the white-yellow substance in Mabel's glass before snapping to the eggnog jug on the kitchen table. "Mabel," he hissed in horror, "are you crazy?"

"What?" she asked in bewilderment, lowering her glass to wipe at the streak of eggnog on her lip.

Gaping, Dipper strode over and picked up the jug. His suspicions confirmed, he thrust it out and cried, "Mabel, eggnog has alcohol in it!"

The fourteen-year-old froze. "What?" she repeated, now with astonishment.

"It's got rum in it," stressed Dipper. "As in it's not a drink for people who are underage."

"How was I supposed to know?" defended Mabel. "I thought eggnog was just a regular drink!"

"It can be, if you buy it without the traditional alcohol," said Dipper patiently. "But Grunkle Stan bought it. You think Grunkle Stan bought teen-friendly eggnog when he didn't have to?"

Having to concede with that, Mabel rubbed the back of her neck sheepishly. "Whoops. Well, that explains the aftertaste. But other than that it tasted like custard. You should try some."

Dipper stared at her incredulously. "I will ask you again. Are you crazy?"

"Hey, a sip isn't going to kill you. Besides, it's the holidays. After this we'll stick with the non-alcoholic version."

Staring at the remaining eggnog in Mabel's glass, Dipper struggled internally for a moment. Unable to dispel his curiosity, he took a cautious drink, rolling the flavour over his tongue. "Yeah," he finally conceded. "It tastes like custard."

Heavy footsteps sounded in their direction, causing both to whip their heads towards the door, eyes wide. Stan appeared in the entryway and he paused at the scene he came upon. Staring at his nervous and guilty niece and nephew, he let his gaze linger on the eggnog for a short moment as his brain processed what they had just done.

"…there's alcohol in that."

"I didn't know," squeaked Mabel. "Dipper just told me."

"She told me to try it. I couldn't help myself," added Dipper meekly. "It was just a tiny sip."

Rubbing a hand down his face, he inwardly cursed his poor judgement, for he should have known that Christmas-crazy Mabel would have gotten her hands on it eventually. "Right. You stick that back where you found it," he ordered Mabel. "You—stop letting your sister tempt you," he directed towards Dipper. "You're supposed to be the one who reigns in her enthusiasm."

The boy nodded. "Right. Sorry. Lapse in judgement."

"Don't touch this stuff again until your twenty-one. Stick with soda. Don't tell your parents this happened." He then thought over his words and added, "You know what, don't tell Ford either."