Author's note: a little one-shot for two challenges: the BBC Sherlock challenge, on the Harry Potter challenges forum, and the Christmas Tree Event at the lovely new James/Lily forum Key Limes.

Pairing: James/Lily, with a fair amount of Sirius as well because he's my favourite character

Disclaimer: None of the characters are mine, they're all JK Rowling's.

Lily wasn't entirely sure how, when or why she had agreed to do this. Yet she found herself ringing the bell to the Potters' front door on Christmas Day. James and she had been dating for three months – only three months, as Lily's mother had pointed out to her, and Lily was going to meet James's parents for the first time. Well, properly meet them. She had seen them a couple of times over the years picking up James from the train platform, but had never been introduced to them.

"It will be fine," Lily muttered to herself.

The door opened, and Lily painstakingly stuck a cheerful smile to her face. She knew her cheeks were already red from the cold, and she was sure they would not go any less red any time soon, as she would for sure be subject to an intense scrutiny. She had heard of how much James's parents doted on him, and she could only hope they would think she was good enough for their son.

"Merry Christmas!" boomed a deep voice.

Lily stared uncomprehendingly at the beaming, handsome face in front of her.

"Oh, so – you're here, too?" Lily said, her smile fading.

The grey eyes narrowed and stared back at her coolly.

"Hide your excitement, please," Sirius said. "You're making me blush."

Sirius stepped back to let her in, and Lily took a deep breath as she stepped in the high-ceilinged hall, which was bigger than her parents' living room.

"Sorry, Merry Christmas, Sirius," Lily said grudgingly, frowning down at the bouquet of flowers she was carrying. "I just didn't know you'd be here."

"Where else would I be? It's not like I've got another family to go to, you know."

Lily felt a pang of guilt at Sirius's words. She could see he was trying to make fun of the situation, but he was failing miserably. Lily could not always reconcile this idea of Sirius with the brilliant but annoying boy who was so fiercely protective of James that he had pulled an indecent amount of pranks on her lately.

"Where's James?" Lily said quickly, as she took off her coat.

Sirius brushed the hair out of his eyes and looked at Lily's conservative white blouse with the faintest hint of a smirk. Lily could feel herself blush already. Maybe she should have worn something else? Something that did not make her look like a soon-to-be eighteen-year-old wanting to appear older than she was, to get in her boyfriend's parents' good graces?

"In the kitchen helping his parents. Thought I'd go and open for you, give you a minute to pull yourself together."

"Oh," Lily said. "That's actually very thoughtful of you."

Sirius grumbled something under his breath, rolling his eyes.

"Alright, Sirius, it's Christmas. Maybe you don't know the drill, but I do. Christmas is the time when you forgive your most annoying relatives and suddenly find them jolly good company. I'm sure you and I can do that. Do you trust me?"

"Absolutely not. Who do you think I am?"

But Lily saw that he was hiding a smile.

"Well, I think you're a terrible person," Lily said lightly.

"You and the rest of the world, sweetheart. Get in line. Me and the general population haven't been on speaking terms since 1972."

"Maybe that's because of all those pranks you pull," Lily said. "Like the recent one, on my hair."

Sirius smiled broadly.

"Yeah, well. In my defence, it was very funny. OK, probably not a great defence."

Sirius turned his back to her and headed towards what Lily supposed was the kitchen. She looked around in awe as she followed Sirius, taking in the great size of the rooms and the good, albeit slightly old-fashioned, taste of the furnishing and decoration.

"You'll be alright," Sirius said, not turning to look at her. "They're the best."

The knot in Lily's stomach loosened considerably when she caught a glimpse of James's smile as she entered the kitchen.

"They love you, Lily," James whispered excitedly two hours later, as he came back from the kitchen into the living room where Sirius and Lily were sitting. "Not that I had any doubts they would."

James sat down next to Lily on the comfy red couch. Lily snuggled up against him. The Christmas lunch had been a success at all levels. James's parents were charming and made her feel welcome at once. Although James's mother had subjected her to a rather long interrogation, she seemed to have answered everything to Mrs Potter's satisfaction. Lily had even indulged in two pieces of Mrs Potter's delicious homemade apple pie.

"I did have my doubts," Lily said. "But I guess we can do pretty much anything if we put our mind to it. You know, I bet we could rule the world if I took up martial arts and you stopped making stupid puns."

"Maybe. Unfortunately, I love my puns too much. Ruling the world will have to wait."

Lily grinned. She could feel the tension in her neck and shoulders ease, now that she had passed the test with flying colours.

"And I wouldn't change you for anything in the world," Lily said, planting a chaste kiss on James's lips.

"Gross," Sirius commented from his armchair opposite them, wrinkling his nose and looking away.

"You'd better get used to it, Padfoot," James said, smiling. "I don't think we're planning on stopping any time soon, are we, Lily?"

"Absolutely not."

"All right," Sirius said, sighing. "Thank goodness your parents let us drink in the house for Christmas, Prongs. Best gift ever. I'll just drink until you two become two blurry faces and eventually a big Jamesandlily blob."

"Ah, don't worry, Sirius, you'll find your own blob when you grow up," Lily said.

Lily and James both chuckled at Sirius's offended expression.

"Excuse me, but my goal is not to become part of a blob," Sirius said, his head held high. "I am my own blob. Once upon a time, maybe I shared it with someone else, but then he picked up the nearest red-head and broke my heart."

"Oh, Padfoot," James said, grinning. "You know I'll always love you."

"I didn't say it was you," Sirius said, sticking out his tongue at James.

Lily laughed again, feeling her cheeks flushed with Christmas cheer and the warmth of the Potters' fireplace.

"Come on, Sirius, come here," Lily said.

Sirius made a great show out of condescending to sit down next to her. Lily put one arm around James's shoulders and the other around Sirius's, feeling completely relaxed now and almost like she was at home; but then again, maybe she was.