(AU, I imagine them to be seventeen/eighteen)

Green looks up from his current occupation of teasing Leaf at the sight of a corner of a book breaking the edge of his vision. He finds Red standing there, offering an exercise book-textbook combination, and Green quickly recognises yesterday's maths homework. He sighs, brushing an auburn lock of hair from his eyes with a light smirk.

"Again, Red? Weren't you listening in class?"
"Question fourteen." He offers the books slightly closer, and Green has little option but to take them. He ignores Leaf's snort and barely notices as she moves off to converse with some other girls in the common room.
"Sit there." Green points at the chair next to him and Red obediently nestles where told. "What's the problem with it? Iterative methods, wasn't it? They're not hard..." Red merely points to the place in his working he's reached, where Green finds a jumbled mess of numbers and letters.

He sighs, rubs his eyes and clicks his fingers for Red's pen, not bothered to dig his own out of his bag. Once he receives it, he puts a cross through the working already there and angles both the pen and the book at Red.
"If you just wrote more neatly, it wouldn't be a problem. Write the equation out." The ebony-haired teen does so in a scrawl that might seem to most as illegible, but Green (secretly) prides himself on being able to read it. Which is some feat considering that occasionally, Red himself can't read it.
"Now you re-arrange it. You did this, I saw you."
Red just looks at him blankly, before offering him the pen again. Green takes it with diminished enthusiasm.

"Fine, I'll do it for you. Happy? Teacher won't be, seeing as this is the third time this week!" He sets about sorting the equation, shifting x around while quietly describing to Red what he's doing, because he refuses to outright do the other's homework for him. Even though he suspects Red knows how to do this. Why exactly he would bluff eludes Green, but he's sure there's a decent reason there somewhere.

Once finished, he sets the pen down and looks up at Red again, finding himself disarmed by the happy grin on Red's face. Green immediatedly suspects something, although what, he's not sure.
"What's that look for?"
Red smirks, smirks, (it's a whole year's worth of emotions in half a minute) grabs the pen and flicks to an empty page in his maths book, and scribbles a line at the bottom of the paper. He then angles it towards Green, still smirking.

I love you, in Red's awful handwriting, lies across it, glaring in its simplicity. Green gapes at it, wondering what on earth happened to cause this, because one moment it was maths then this.

"You are the most insufferable idiot in the world!" There's no malice behind the statement, and yet Green still feels like Red is teasing him, as he leans far too close just to whisper 'I know.' into Green's ear before he leaves, gathering his things.

A somewhat flustered Green is pleased to find that Leaf missed the whole debacle.

I don't know what happened. One second I was (un)happily revising maths, then the next, I was thinking of this. I thought it was sort of amusing, so I decided to post it...

This may have also sparked an idea for a 5+1 fic, in which Red inadvertantly causes Green trouble/embarrassment five times, and once where Green gets him back. I'll see...

Iterative methods are something we've just done, so yeah. Not hard, just a bit annoying really. Red should have been a little more subtle.