November 18, 1979

Lily Evans couldn't help but notice that her boyfriend's best friend, Sirius Black, had begun acting a lot nicer in the past week or two. Sure, ever since she and James started dating, he'd been fine, and she realized that if you dated James, Sirius was just part of the package.

But it seemed like now it wasn't just her boyfriend looking out for her, it was Sirius, too. The way he'd dart in front of her if there was any potential danger around. He helped her carry the groceries, held doors open for her, didn't want her moving heavy objects, all in all just being there for her. It definitely wasn't flirtatious, just very brotherly.

Since she was only a nineteen-year-old girl, fresh out of Hogwarts, Lily wasn't focusing too much on "adulting" right now. She and her boyfriend still lived with his parents, in a nice manor. Sirius had moved out and gotten his own horrible bachelor pad—it was a simple studio that desperately needed a woman's touch. But she was still in the Potter Manor with James.

On this particular November day, Lily and James were participating in one of their favorite pastimes, which was throwing a ball or a squeaky toy or something and having Padfoot fetch it. Sometimes he would just catch the ball and run away with it, and they'd have to chase him, and sometimes he'd jump on one of them and knock them over. It was the first time in Lily's life she'd been thrown off the couch and slobbered all over by a giant black dog.

As the day wore down, Padfoot jumped up on the couch and curled up in between James and Lily. She stroked the dog's head and watched his floppy ears go back; she took off her Gryffindor scarf and tied it around his neck, and James laughed. Lily was just feeling more loving in general, lately. They watched the sun sink slowly beneath the trees, and Padfoot put his paws and his head on Lily's lap, then shut his eyes. It was crazy to her—this dog that could bite her arm off if he wanted to was so gentle to her. That wasn't how she knew him back in their school days.

Finally, Padfoot turned back into Sirius, and flew home on that motorcycle of his. James had a double bed at home, and when Lily moved in with him, she slept there, too. It was so nice to have a boyfriend to cuddle up with. She'd lean her head on his chest and he'd wrap his arms around her, or if she wanted more space, she'd turn on her side and he'd kind of embrace her from behind. If she was going to bed early, and James wasn't tired yet, he'd always tuck her in, push her hair back and kiss her before she went to sleep.

…

"Prongs…PRONGS!"

"Whuh?" James woke up to the sound of the magic mirror sitting on his nightstand. When he rubbed his eyes hard and put on his glasses, he saw that it was Sirius, of course, looking a little stern.

"Apparate out to my flat, dude," Sirius was saying. "It's important."

"It's the middle of the night!" protested James.

"I don't care. Just don't wake up Mrs. Flower, all right?"

"Fine."

James pulled on sweatpants and an old T-shirt and in a couple seconds he was at Sirius's flat. The hallways reeked of cigarette smoke and there was an oddly-shaped fountain, made out of white cement, in the lobby, but it had recently broken. There was a bathroom, a main room and a kitchen, and James agreed with what Lily had so aptly observed when she first saw the main room: "It looks sort of like a drawing room and a bedroom had a baby together—and then that baby threw up." She also remarked that there were probably four times as many clothes strewn all over the floor than there were actual furniture pieces.

Still, James was not completely bothered by all this mess. He was just glad to see his friend. After all, if it had been too clean, it might have been uncomfortable.

"I'm here," he called.

Sirius clapped twice and that turned on the lights. He was still dressed, smoking a cigarette. He'd stopped smoking around Lily, James noticed, but maybe that was just because she'd always put the flame out with water from her wand. She told him he was going to have a heart attack one day, and he never listened.

"Come over here," said Sirius, patting the seat beside him on the discount bed he probably got at a flea market.

"Where'd you dig this thing up?" James said jokingly. "The dump?"

"Goodwill," Sirius replied loftily. "It's called being frugal, Prongs, and it's not a crime."

"Whatever," James yawned. Even though Uncle Alphard had left Sirius with plenty of money, he was still such a cheapskate. "What do you want?"

"Look…something is definitely up with your girlfriend, dude," Sirius told him.

"She seems the same to me."

Sirius sighed. "You know about my canine sense of smell, don't you?"

"Well, duh," said James. "Becoming Animagi was my idea."

"Okay, similarly to how my job in school was to sniff out when teachers were coming," Sirius said, "I'm around you and Lily all the time, and I can tell when anyone suddenly smells different. You know, people are walking piles of pheromones and hormones, secreting odors wherever they go, that let me figure out how they're feeling."

"If you're trying to say it's 'that time of the month,' it isn't," James said. "That's not for another week."

"I know," said Sirius. "But something's different about her. I can just tell."

"Different how?" asked James.

"Well, I guess she's sweatier," Sirius listed. "Waaay more pheromones and hormones. Moods changing a little more rapidly, a little greasier in the hair, but overall, it's a pleasant smell."

"Like you said, it's a weird ability to have, but it can be a useful one," James told him. "Maybe she's sick, huh?"

"She's been sick before, too. That's not it."

"What is it, then?"

"I don't know." Sirius shrugged. "But my sense of smell is even stronger when I'm in my dog form…I could definitely smell something's up. I just don't know what."

"Maybe you could smell a bunch of different things and see whether they match up," James suggested.

"There's an idea." Sirius smiled.

…

The next day, Lily was a little tired, so she spent that day napping. Meanwhile, Sirius and James went to do a sniff test. They ended up at a Muggle pharmacy and wandered all the aisles. Maybe, they figured, Lily was on some new antibiotic and she'd forgotten to let James know. But when they hit Aisle 2, a very similar smell hit Sirius in the face. Without a word, he raised his eyebrows and pointed down that aisle.

"Start tracking it," James told him.

Nobody was watching, so Sirius discreetly (as much as possible, anyway) turned into his Animagus form, and James put the leash and collar on him. Halfway down the aisle, Sirius stopped, transformed again, and—

"Oh my God, I should have known!" Sirius said, a little too loudly.

James looked like he'd just been shot in the heart, the way his mouth was open, but he didn't really seem to be breathing. They were right next to the pregnancy tests.

It all made sense now to Sirius, though. He often followed his instincts, and lately they had been telling him he needed to be gentler with Lily, that he needed to help James protect her from danger, that he shouldn't knock her over in dog form and he had wanted to cuddle up instead. This was the reason why.

Sirius's immediate concern, though, was James, who really didn't look so good.

"Um…Prongs?" said Sirius uncertainly. "You okay?"

"Are you trying to tell me," James finally choked out, "that I'm going to be a father at only nineteen?"

"Yeah, looks like it."

"What are my parents going to say?!"

"Maybe they'll say that they're glad to have a grandchild."

"This is going to go horribly." James shoved his hands in his pockets. "I'm sure everybody will just be really judgmental."

"Don't tell me you're not going to go through with it!" Sirius said, aghast.

"Of course I am!" James snapped. "What do you think I am, an abandoner?"

"No." Sirius dared to grin just a little. "I know you better than that."

…

Lily awoke from her nap to James gently shaking her awake. Sirius was there, too.

"Hey, Mrs. Flower," said James, stroking her long auburn hair the way she liked. "How are you feeling?"

"Good," she replied, blinking to get the sleep out of her eyes and smiling at him.

"Well, I've got something for you," James said, a little uncomfortably, Lily thought. But she was unfamiliar with what he took out of his pocket.

"What is that?" she asked.

"It's, um, it's Potiogravida-PN," James hesitated, and Sirius nudged him. "Sirius and I stopped at a Birth Center, and we got this potion, and, uh, you dip your wand in it and…it tells you if you're pregnant. It also doubles as a pregnancy supplement to lessen symptoms."

"What?" cried Lily. "Pregnant? Me? No, I-I can't be!"

"You can be, if you had a bareback romp in the sack," Sirius offered, and James glared at him.

Lily's hands shook as she slowly reached for her wand, which was resting on the nightstand beside her. James unwrapped the potion, which looked and smelled just like water, and she dipped her wand in.

"If the potion turns silver, you're not pregnant," James said. "And if it turns gold—"

All three of them gaped as the goblet of Potiogravida-PN suddenly glowed gold, then turned clear again.

"Then I am," Lily whispered. But she was surprised when James sat down next to her and threw his arms around her.

"You don't have to worry, Lily," he declared. "Sirius and I will be here all the way. I'll marry you, even, and we can move into our own house, and we can raise our baby all together as a family. All right?"

Lily looked into James's hazel eyes, which were filling with tears.

"Do I have to marry Sirius, too?" she said jokingly.

"Nah, I can settle for brother-in-law," Sirius chimed in, and hugged her too.