A/N: Hello! Although it feels a bit dorky to say that, it feels rude not to. Anyway, as the description says, this story is based on the Nissan pairing. Yes, Nissan. That's my pairing name for Nelson and Lisa- and if I may say so myself, it's quite clever, especially considering their romance started with vandalism of another type of car. ^^

I'm guessing most people interested in this pairing have seen the episode "Lisa's Date With Density" (love that pun, especially as it's kind of fitting), but if you haven't, or if it's been a while since you've seen it and you've forgotten the main events, I'd recommend that you watch it. That's because parts of this fanfiction may be a bit confusing if you don't have basic knowledge of the events that took place in that episode.

Please leave reviews. Let me know what you think; I want to know your opinion!

DISCLAIMER: I don't own "The Simpsons" in any way, shape, or form. Nor do I own Nissan. I just think the brand name is fitting for this pairing.

Nelson stepped outside, pushing his arms through the sleeves of his coat as he did so. A gust of wind slammed the front door shut behind him. For a moment he just stood there in the chill November air, hands in his pockets, wondering how he would get himself out of this mess. Everything in his life seemed so twisted and messed up that he had no idea how he could ever possibly straighten it out again. Ever since his sister had returned…

He quickly banished that thought. It wasn't Ashley's fault, he reminded himself. And he was happy to have her back, to know she was safe after he'd presumed her dead for years. But at the same time…

What he needed was to get away, just for an hour or so, he decided. Not three seconds after that thought appeared in his brain, he realized he knew the perfect place where he could go to take his mind off of his problems. He hadn't been there for months, and in truth he'd been struggling to stay away, but he knew it would help, at least for the moment. With a small sigh, he tugged his keys out of his pocket and walked down the driveway to reach his car parked on the curb.

Five minutes later, he was pulling into a parking space in front of the Kwik-E-Mart, Springfield's local supplier of Squishees, Slim Jims, and Laramie cigarettes. Nelson closed his door and peered upwards, identifying three familiar figures stretched out on the flat roof of the store. Of course they were here. They hadn't noticed him yet; they were focused on an item in the middle one's lap.

As Nelson approached, Jimbo Jones looked up to grab an unopened can of beer, and his eyes landed on the younger boy. Nelson kept walking towards the Dumpster on the side of the building, feeling his old friend's gaze focused on him all the while. "Going Dumpster diving for dinner again, huh?" Jimbo called.

"Shut up," he responded, prompting laughter from the other two young men on the roof, Kearney Zzyzwicz and Dolph Starbeam. Nelson hoisted himself up onto the closed half of the Dumpster, took a second to gather his breath, and then repeated the process to lift himself onto the roof with the others.

"Dude, where've you been all this time?" Dolph asked, setting his Playboy magazine aside for the moment and turning to gaze at the younger boy.

"We thought you'd skipped town or something," Kearney put in. "I said you'd probably gotten into some fancy college and couldn't be bothered to hang out with us losers anymore."

Nervously, Nelson laughed, plopping down beside Jimbo and stretching his legs. "That'd never happen. You know I'd never get into any college other than community," he replied, ignoring the second half of Kearney's prediction, because it was true, at least in part. He had been avoiding them. Of course, he wasn't a complete loner; he'd met a couple guys at school, Andrew Carson and Sam Bennett, whom he got along fairly well with. Both Andrew and Sam were his own age, seventeen, not in their mid-twenties like these guys, and they both came from relatively stable households, unlike his old friends- and himself.

Kearney shrugged in agreement, taking a swig of his beer. As they always had, the trio had assembled a picnic on the roof and were now enjoying a feast of Duff beer, fries from the Krusty Burger a couple blocks down, and various sugar-loaded food products that could probably only be called "food" by a stretch of the imagination.

"What have you been doing?" Jimbo asked curiously.

Nelson hefted a sigh. He hadn't been doing anything particularly interesting. In fact, he didn't know what to do. That was why he'd come here- not for advice, really, but for some support, the type that could only come from people who had gone through the same problems you were facing right now. Even though Nelson was well aware of the fact that all three of his old friends were as dumb as rocks, their lives were just as screwed up as his, and they would understand where he was coming from. "My sister came back the other day," he said at last.

"Your sister? The one who kept running away from foster care?" Dolph squinted at him.

"No, the other one," Nelson answered drily. The redhead scowled, flipping him off, which he ignored. "She had a police escort," he added after a pause.

His friends looked impressed, but he'd expected that reaction from them.

"She sounds hot," Jimbo commented.

Nelson punched him in the shoulder, feeling nauseous at the image that those words brought to mind. Dolph looked vaguely sick as well. Kearney faced the youngest of his friends, his forehead wrinkling. "Isn't your sister, like, twelve?"

"Yeah, she is." He shot another glare at Jimbo, whose face was rapidly paling as he realized the gravity of what he'd just said.

"She's-she's twelve?" The black-haired man spluttered for a few seconds, then choked, beer splattering from his mouth rather disgustingly. "I thought she was- I thought she was older-"

"Dammit, Jones, I just lost my appetite for Playboy." With a scowl, Dolph rolled up his magazine and stuffed it away in the fast food bag lying beside him.

Kearney sat up indignantly. "I was looking at that!"

"You have a girlfriend," Dolph pointed out, tipping his head back to stare at the sky as if bored. "Can't you get her to send you some pics? Same to you, Jimbo. I brought that Playboy for me, not either of you."

Nelson sighed softly, letting the familiar sounds of their arguing voices wash over him like waves sweeping up on the shore. It took him a moment to register that Jimbo was staring at him, his eyebrows raised expectantly. It was clear he'd just asked a question that his friend hadn't been paying attention to. "What?"

"You have a girlfriend yet?" Jimbo repeated, somewhat impatiently.

Nelson shook his head. He'd gone out once or twice with girls he met through Sam and Andrew, who were in a band, but something just hadn't felt right. The date would seem to be going okay up until the kiss. Then it was like his body shut down on him- not moving, not responding, nothing. He hadn't been able to sense anything; he couldn't think or feel. He was just… stuck there, with his lips against some random girl's, feeling like a robot. Something simply felt unnervingly wrong, and as much as he struggled, he couldn't get himself to enjoy the sensation.

He didn't think he was gay, because up until that kiss, he felt attracted to the girl. He noticed any pretty features she might have had, and he genuinely wanted to get to know her better. But the kiss always caused all of that attraction to vanish in an instant.

"Check it out." Kearney's voice broke into his musings. "Think I could get away with taking that baby for a spin?"

It became clear that he was referring to a shiny silver car sliding neatly into a parking space below. Nelson, who had always appreciated a good car, couldn't help admiring it for a minute. "Looks like a BMW," he observed.

"How can you tell what kind of car it is from this high up?" Jimbo asked incredulously. Nelson shrugged. He had a nice eye for detail, but his old friends didn't really know that. They'd hung out with him often enough in the past where they should have learned this fact by now, but truthfully, they didn't seem to pay much attention.

The driver's door swung open in a wide arc. "If this was a TV commercial, some hot chick would be walking out right about now," Kearney whispered, leaning eagerly over the edge of the building. The other three followed suit.

If they were hoping for that hot chick, they were in for a disappointment. The voice that drifted up to them was definitely male, with a slight Irish accent- which made sense, considering he seemed to be talking about living in that country. "It's beautiful out there," the guy said, exiting and walking around to the passenger side. "So green and unpolluted. Where my family lived, in Cavan…" He opened the passenger door.

"'Where my family lived, in Cavan,'" Kearney mocked, putting on a horrendous imitation of an Irish accent. Dolph and Jimbo snickered, but Nelson's ears were prickling, as they could hear a vaguely familiar voice…

"Shut up!" he hissed, punching Jimbo in the shoulder, mainly because he was closest. Fortunately, all three of them obediently fell silent, which made the voice that had just spoken quite clear all of the sudden.

"-I've heard it's gorgeous," the person getting out of the passenger seat was saying. This voice certainly belonged to a girl… and Nelson immediately recognized which girl it belonged to…

A moment later, Lisa Marie Simpson slid to the ground. His breath caught, even though he was somewhere around ten feet above her, and the height made it difficult to see her face. She was beautiful, just as she always had been, but there was more to it than that. A memory tugged faintly at the back of his mind; he swallowed hard, closing his eyes for just a moment…

To his surprise, she didn't smell like the dusty old novels she always had her nose buried in, nor did she smell like tofu or some disgusting green stuff from her vegetarian diet. No, Lisa smelled like coconut and apricots, which was perhaps an unusual combination, but definitely, he discovered, an appealing one. Unsure what he should be doing, having never kissed a girl before, he merely sat there, keeping his lips on hers, letting her aroma sweep over him, feeling the warmth of her nearby body… It was actually quite a pleasant sensation.

He opened his eyes slowly, his heart hammering. What would she do if he called down to her? What would he even say? Just a brief "hey, good to see you"? Would she think that was odd, though, given that they hadn't really spoken in years? Besides, he was with the same three guys who had split them up nearly eight years ago, and she wouldn't know that he'd been trying to stay away from them. Lisa wouldn't know that he'd matured, and he realized now that Jimbo, Dolph, and Kearney had been a negative influence on him as a kid, and continuing to hang out with them now would inevitably only lead to trouble. Through her eyes, Nelson would appear the same as always. Maybe, to some extent, he was, he thought gloomily.

"So are you," the Irish guy down in the parking lot said.

It took Nelson a second to register that the BMW driver had just called Lisa gorgeous. His muscles tensed instinctively, preparing for a fight- but what was he going to do? Jump down from the roof to beat the guy up, then sweep Lisa up into a passionate kiss? Yeah, right. He knew better than that. Violence wouldn't get him anywhere with her. Besides, he reminded himself, he hadn't seen any evidence yet that Lisa liked this guy back. That helped his muscles relax- somewhat.

"Hey, uh… you okay?" Jimbo asked in a whisper, eyeing his friend warily.

"I'm fine," Nelson muttered. "Something I ate." His eyes remained glued to the scene in the parking lot. Lisa's giggle, which he'd only heard her make when she was nervous, drifted up to his ears. The boy with her drew closer to her. She didn't move back. Nelson knew he should avert his gaze, but he couldn't force himself to turn away, and so he watched, with excruciating clarity, as the Irish boy pressed his mouth against that of the only girl Nelson could ever remember truly wanting. And he was completely powerless to stop it.

He wasn't sure how much time had passed when they split apart, murmuring a bit before pushing through the doors of the bookstore to the right of the Kwik-E-Mart. He stayed there, frozen, half-leaning over the edge of the roof.

"Whoa," Jimbo said, breaking into his thoughts. "You sure you're okay? You're shaking."

Nelson realized he was right. His body had begun quivering at some point, although he scarcely felt the cold air. Inhaling deeply and slowly through his nose a few times, letting it out through his mouth, he shrugged, succeeding at last in dragging his eyes away from the now-empty lot. His nails had been digging into his palms, he noticed with surprise, uncurling his fists slowly.

"You look like you're gonna murder someone," Kearney supplied, then added hastily, "Not that I'd have any experience with what that looked like."

Dolph didn't say anything, just sat there, tilting his head as if trying to puzzle something out. Realization dawned on his expression. Nelson wasn't sure he was too pleased with that.

"What a loser," the redhead said, glancing down again to indicate the Irish boy, although he had now vanished. "Rich bastard." He spat onto the sidewalk. Nelson stared at him for a second, baffled. There was no way Dolph was trying to make him feel better- since when had he, or any of the three of them, done anything that even acknowledged the fact that they had emotions?

Kearney seemed to catch on after a second. "You know what? I think we should wreck his car," he said, reaching for a bag of chips lying beside him. To Nelson's amazement, rather than grabbing a handful for himself, Kearney offered the bag to him. "Here, take some," he urged, almost as a command. A bit mystified, the brown-haired boy obeyed. What was going on here?

"I say we set it on fire," Jimbo put in enthusiastically. He didn't seem to fully grasp the situation, which was typical of him- but as for the other two…

Maybe Nelson was imagining things. He settled back on his hands with a sigh, lingering for a moment on the tempting image of Mr. BMW stepping out of the bookstore, hand-in-hand with Lisa, only to find his once-valuable car now a smoking black heap of ash. He'd probably go ballistic.

He smiled a little at the thought- then felt the pressure of someone's eyes fixed directly on him and swiveled his head around to face Dolph, wearing a knowing smirk on his face as he watched his youngest friend. Starbeam had always been the quietest of the group, but Nelson had learned that was because he preferred to observe everything from the shadows, then use the information he had gathered however he saw fit, which never benefitted the object of his scrutiny. He was no smarter than Kearney or Jimbo, necessarily… but Nelson knew his redheaded friend had a certain knack for perceiving when a topic was uncomfortable to someone, and then for exploiting that weakness when a person least expected it.

Nelson wanted to look away, but doing so would only alert Dolph to the fact that something was indeed going on. Instead, he held his old friend's stare steadily. Whatever Starbeam was scheming, it couldn't be anything good, and Nelson had the sense that out of all three in the group, Dolph understood the most about his feelings for Lisa, and he wouldn't hesitate to use that to his advantage.

But Nelson wasn't about to let him. God knew his "friends" had interfered with his love life enough already, and although Dolph seemed ready to interfere with it once again, there was a way to stop him: to turn the issue into a non-issue. That was to say, to reach a point in his relationship with Lisa that he genuinely felt satisfied with.

He had no idea how he was going to achieve such a task.