Anyone who knew James Potter knew that he was not a particularly jealous person. He was not territorial or obsessive. He was very secure in his relationship with other people and never doubted how they felt about him.

But James was still a human being and just because he was not a jealous person, didn't mean that he didn't get hit with occasional burst of jealousy once in a blue moon. In fact, he could count the amount of times he had been jealous in his life on one hand.

There was the time when he and Lily had officially become friends and he found out that Lily was going on a date with Amos Diggory. The feeling quickly passed as he reminded himself that he was in no position to be feeling this way towards Lily as she was her own person.

There was the time he caught Lily and Sirius sneaking back into Hogwarts after an impromptu trip to Hogsmeade for some chocolate from Honeydukes. The jealousy quickly passed when James reminded himself that Sirius was practically like a brother to him and there was certainly no way that Sirius would ditch him for Lily that quickly.

And lastly, there was the current situation with James seconds away from making a complete ass of himself in the middle of Tescos at eight in the evening.

He had wandered away from Lily for all of five minutes to grab some cereal and when he found her again, she was talking to someone whom James assumed Lily was quite acquainted with. Her head was thrown back in one of her full-bodied laughs that James loved, her hair swinging around her as if Lily was in a shampoo ad.

And the bastard making her laugh was just eating it up. James could see it, he could just see it from all the way down the aisle where he stood glaring. The man just stood there undressing his girlfriend in his head, and he was doing it right in front of James's cereal. How dare anyone think of Lily in that way in their mind, who thinks thoughts like those? This man didn't even know Lily and he was already having these inappropriate thoughts, the utter disrespect.

And while James stood seething at the forwardness of this man's thoughts, the reality of the matter was that whoever Lily was talking with had nothing more than a gentle smile on his face as he spoke. And that Lily couldn't even remember what the man's name was even though less than a less minute had passed since he told her.

James's reactions were forgivable in the moment, after all, not many people are thinking clearly at the end of a long day without any food to eat.

Lily leaned forward, still laughing, and lightly brought her hand up to rest of the mystery man's arm and continued to chuckle, to the annoyance of James. Watching the love of his life laugh so hard at another man's joke was the most obscene thing that James had ever seen in his life.

At least in that moment.

And then the straw that really broke the camel's back was when the man leaned towards Lily, and said something to her that James couldn't hear which set Lily off on another round of laughter. He was far too close to his girlfriend, they were sharing breath at this point, it was too much. How dare he invade Lily's personal space like that, whomst did he think he was, the bloody Prime Minister or something?

And before James could really think through what he was doing and remind himself that he was being an ass and that he was about to become an even bigger ass right in the middle of Tescos, he was off. His strides were long and strong, the deer in him had taken over, before he knew it he was next to Lily. He had an up close at her shoulders shaking, which did nothing but incense him even more.

"Oh James, there you are," Lily said, her smile widening at the sight of him which made James just a little bit less irritated but not by much. "I was wondering what was taking you so long."

"I got distracted," James tried to say as nonchalantly as possible and attempted to give the usual gentle smile that he reserved especially for Lily because she was his little marshmallow.

(He was very far gone on this poor girl.)

Lily grabbed his right hand with her left and pulled him closer to her side, using her own right hand to gesture towards the mystery man. "This is … an old schoolmate of mine."

The fact that Lily couldn't remember the name of the man she was talking to went right over James's head, and so did the pleading look on her face that was clearly asking him to give her some material with which to say goodbye and move on with their shopping.

"Thrilled to meet you," James deadpanned, sticking out his left hand for it to be shaken.

"And you are?" the man asked questioningly, pleasant smile still pasted on his face.

"My lovely boyfriend," Lily jumped in and let go of James's hand to wrap it around his waist. James couldn't help but feel smug as Lily pulled him even closer and rested her head on his chest.

"Oh, how wonderful, I'm so happy for you two," the man said, genuinely pleased that Lily seemed to be so in love. It probably should have made James happy that this man didn't appear at all jealous or bitter at this new discovery.

What happened next was something that James couldn't explain. He leaned down with every intention of leaving a chaste kiss on the top of Lily's head, as boyfriends were wont to do. He would swear on Sirius's life that that had been his initial intention but somehow he found himself leaning even farther down, past the top of Lily's head, past her cheek and found himself at her neck. He couldn't say what exactly compelled him to do what he did next, he was only vaguely aware of what he was doing, but before he could stop himself, he had taken one long lick from Lily's collarbone to right under her jawline.

With his tongue in case that wasn't evident.

At no point did James break eye contact with the man in front of him.

Lily froze, the man froze, and then James froze. Mystery man had frozen in an expression somewhere between a grimace and shock and kept staring from Lily to James and back again as the silence stretched on. Lily had a very concentrated look on her face, her mouth set in a grim line as if she were listening to a particularly complex explanation of some Transfiguration lesson that McGonagall was teaching. And James just kind of stared into the frozen food in the fridge to his right, eyes frozen wide as he questioned every choice he had every made in his young life.

The silence dragged on for what felt like years to James until the man finally broke the silence.

"Well … it was nice catching up with you, Lily, I-I wish you good luck," the man said and before James could choke out an apology he had disappeared.

Lily turned to James, her lips slowly disappearing into her face as she pursed them in irritation. "Would you mind explaining to me what exactly just happened?"

"I'm not entirely sure," James muttered blankly. And then the next second it hit him. A fun fact he remembered reading in a book about Animagus describing the certain behaviours of animals and James knew exactly what he had done. The truth of it was more painful than if the fact was that he was just an absolute idiot.

He buried his face in his hands and groaned and then shoved them into his hair and gripped at his roots in frustration.

"Oh sweet Phineas I remember now," James moaned out and closed his eyes. "See, the thing with deer is that the stag will lick the does neck to mark his territory if he sees any competition. Sometimes people who are Animagi will experience an occasional urge related to the animal they turn into."

Lily continued to stare at James, her lips pressed into a thin line but try as she might she couldn't stop the edges of her lips from twitching upwards. A giggle eventually escaped Lily as she slapped a hand over her mouth and her shoulders began to shake.

"You're not mad at me?" James asked hopefully as he cracked open one eye and looked at Lily who was steadily turning a darker shade of red with each passing second.

"I'm really trying," she said as she let out another bark of laughter. "But I just can't, it's absolutely ridiculous."

James took the hands out of his hair and relaxed his shoulders as he saw the tears that had gathered in Lily's eyes.

"So, you're not going to give me a good talking to?" James asked teasingly, unable to stop his own grin from spreading across his face.

"I don't think I could keep a straight face through all of it even if I tried," Lily said before she lost herself to the loud cackle that burst from her. James threw an arm around her shoulder and tugged her towards him as he grasped the trolley with his other hand and began pushing it down the aisle.

"Let's get our stuff and get out of here, you weirdo," James said, planting a kiss on Lily's head as she leaned on him and continued to laugh, tears rolling down her face.