It's not like Natsu is stupid… he just doesn't try. Okay, well, he tries sometimes, and when he does, he puts his all into it. The thing is that school is boring and books are boring and studying makes his head hurt.
It's been two hours since he sat down before his math homework and all he has managed to do is learn how to balance his pencil on his nose for 5 seconds, devour a plate of sandwiches drenched in hot sauce, and chase Happy around his room.
He must've started working (if you'd call it that) around four because it's already six in the afternoon and Lucy's light is clicking on. She's got this funny lamp with glittering stars hanging from it that it makes her whole room glow gold; her blinds are down but the light shines through and Natsu jumps up in excitement, hurtling towards his window and flinging it open so that he can easily push up her broken window that can't be locked and wiggle in under the blinds.
He immediately falls onto Lucy's bed, stationed perfectly under the window to catch him, and Lucy sighs in exasperation instead of screaming in shock and terror like she used to.
He can tell it's been a long day for her at work because she doesn't even try to scold him, just grabs a change of clothes and slips into the bathroom to change out of her waitress outfit. When she gets back out, she immediately settles down at her desk to write something, but he's not sure whether it's her novel or one of her letters that he knows he should never interrupt, so he flops onto his back and waits. When she folds the paper and lays it in her locked drawer, he knows the answer before he sees the sad smile on her face, so he pulls her onto the bed next to him.
She lets out a huff of irritation before curling into him and mumbling, "I have an English essay to write."
Natsu frowns at her deadened words and says, "Why do you sound so sad if you like writing?"
She grumbles as his arm shifts so his elbow digs into her ribs, and she wriggles a little until they're both comfortable again. "I just don't feel like it today."
"I have math homework," admits Natsu, propping his chin up on her forehead, but she immediately jerks away with a scowl and yanks on his ear. "Ow! Luce, stop!"
"No, I know what this is! You haven't done any and you need help! This is why you need to pay attention in class," she hisses, but her victory is short-lived as Natsu easily bats her hand aside and scowls stubbornly.
"But the teacher is so boring! I just fall asleep at his voice…"
Lucy facepalms and immediately begins trying to shove Natsu out of her window. "Get your homework now or else I won't help you!" she demands as Natsu laughs.
"I'm going, Luce, don't kill me," he says. "By the way, did you get fatter?"
He's forcibly ejected from her room at once, and she slams her window shut after him, but Natsu isn't perturbed because, hey, the lock's broken; he can go in any time. So he just gathers up his things (with Happy clutched in his arms) and clambers back into her room. He's met with a furious yell that no, she is not fat; if anything, she's been getting skinnier because he's been eating all of her food!
Natsu laughs and Lucy relents and they work on his homework until Lucy absolutely has to start on her essay. Without Lucy's guidance (basically, now that no one's supplying him with answers), Natsu immediately just gives up on the rest of his work in favor of faceplanting on her unbelievably soft bed. Happy curls up on the pillow, and by midnight Lucy kisses him on the cheek before half-heartedly crawling over him to sleep on the side of the bed with the wall so she won't fall off and steals all the blankets as revenge for his snoring.
He doesn't notice, anyways; he only has enough energy left to press a messy kiss to the left of her nose (she cringes and complains about his lack of coordination) before passing out.
"I can't believe you think Erza and Jellal are closer than we are!" complains Natsu, in the middle of trying to keep a pencil on his nose for fifteen seconds now; yep, he's a total overachiever.
Lucy's scowling because he's contradicting her and she was supposed to be having a sleepover with Levy when he interrupted. She'd known this was going to happen and warned Levy beforehand, but still.
"They've known each other since they were kids!" argues Lucy. "And they'd do anything for each other; remember that time Erza was almost hit by a car and Jellal pushed her out of the way? He was hospitalized for two months!"
Natsu frowns petulantly, the pencil falling from his nose. "I'd do the same for you, Luce!" he proclaims, flailing his arms. "We'd do anything for each other, too! And they're just regular neighbors! He can't even climb into her room! That's lame!"
"No, that's nice!" says Lucy, jabbing her finger into his chest. "Jellal probably isn't eating Erza out of house and home!"
"Nuh-uh, 'cause I'm helping you so you won't get any fatter!"
With a strangled cry, Lucy tackles him and starts trying to punch him, but all it does is make Natsu laugh as he puts his hands up to cover his face. Levy's cracking up in the corner and Lucy's mad. "Natsu, get out!" she screeches, shoving him towards the window.
Almost immediately, his personality takes a 360 turn as he launches himself at her, hugging her around a leg and crying, "Don't leave me, Lucy!"
Lucy grumbles and settles back down, Natsu is smug, and Levy has an evil smirk on her face. They all sleep on the floor in sleeping bags and Natsu wriggles into Lucy's because he feels like cuddling and she's like the best cuddler ever, so yeah. She mumbles something along the lines of him not snoring or she'll Lucy Kick him and presses a sloppy kiss on his chin, as per tradition. He kisses her on the forehead and they sleep in the overly heated, cramped sleeping bag.
In the morning, Lucy and Levy watch TV shows as Natsu sleeps some more. In the afternoon after Levy leaves, Lucy and Natsu migrate to Natsu's house to babysit Wendy while Igneel and Grandine are out, even though that's a joke because Natsu is way more of a child than Wendy will ever be.
Lucy makes soup for dinner and they watch it on the couch by the television so they can have a Disney marathon that Natsu protests vehemently to. It's a losing battle anyways, because Disney films are practically Lucy's life blood and Wendy eats the stuff up. Lucy props her legs up on Natsu's lap and shares a blanket with Wendy as Natsu screams at the TV, seemingly energetic until he just burns out like a candle and collapses, snoring.
Lucy is forced to haul him up the stairs and onto his bed before tucking in Wendy. Instead of going back home, she shuffles back to Natsu's room, kisses him on the forehead, and collapses in his bed.
He rolls over and drapes an arm around her waist, drowsily pressing his lips against her temple, and promptly falls back asleep.
When they go to school the next day, Lucy screams bloody murder as they're met with school walls papered with pictures of them curled up together, asleep. Embarrassed, she fumes for a moment, wondering how this could've happened, before screeching, "Levyyyyyy!" and taking off.
Natsu surveys the plastered walls, ruffling the back of his hair and beaming with pride, before heading towards an unsuspecting Gray. "Come fight me, ice prick!"