Disclaimer: I own nothing.

Author's Note: Written for the prompt "you said it would be the only time, but it was only the first."

the things we were taught (and the things we learned)

The first time it happens, they can't look each other in the eye.

Stefan enters the room and Damon is already there, lounging on the bed looking for all the world like he belongs there. But Stefan can see the nervous fidget of his fingers, the way his grin is just a shade too wide. He stares at his brother and thinks, he isn't supposed to be here. He doesn't know which "he" he means.

But Katherine is there, beckoning him in, and Stefan knows he'll let this happen. It doesn't have to change anything. They've known, of course they've known, that they've been sharing this woman for a long time. This isn't any different. He repeats this to himself as he shuts the door behind him (locking it firmly, because he may be a fool, but he's not a careless one).

"Mr. Salvatore, " Katherine purrs, looking up at him coyly. Then, over her shoulder, "Mr. Salvatore."

Damon smirks back like he's in on the joke, but Stefan doesn't miss the way his knuckles tense, the skin going white against his bones. He wonders if Katherine notices too, but her eyes are still on Stefan, tracing his form up and down like she wants to devour him (and god knows, she will). This is how it always is: Damon watches Katherine, Katherine watched Stefan, and Stefan watches Damon.

Katherine hooks her finger through his suspenders, and Stefan feels himself being pulled down to the bed, gently but firmly. Katherine is good at that, making it seem like a choice. But he knows as well as his brother does that they have no control in this matter. If either of them bolts for the door they'll find themselves pinned to the bed in an instant. Might as well play along. He prefers Katherine's smile without fangs.

Katherine slides back on the bed, and Damon sidles up to her, ready for instruction. Katherine kisses him, slow and deep, and it makes Stefan's stomach tighten. His face flushes hotly, and he looks away.

But then Katherine's hand is on his cheek, and she's turning him back toward her, claiming his lips for her own. Stefan tries not to search for traces of his brother on her tongue, but Katherine tastes just a bit spicier than usual, and it makes Stefan moan before he even registers the difference. His heart is pounding already, and he can feel Katherine grin against his lips. He wants to run, wants to hide under his covers and never come out, but his brother was always the one to rescue him from the monsters, and his brother is here, so he stays.

Katherine breaks away and looks at them both expectantly. Damon sheds his shirt before getting to work on removing Katherine's corset, deft fingers unthreading the laces in an efficient, practiced manner. Damon only has eyes for Katherine, and Stefan tries to emulate his brother in that regard. That's what younger brothers do. (This is not.)

Before long they are both naked, and Stefan is taken aback by their beauty, all dark hair and pale flesh and secret sin. Katherine kisses Damon again, her hands gliding down his arms, his hips, lower…Stefan gasps at the same moment Damon does, and the world accelerates with the tempo of their breathing.

Katherine lets him go, job only half-done, and Damon looks dazed, lips swollen and eyes glassy. She reaches for Stefan, and he goes to her gladly, ready to lose himself in the woman he loves. He kisses her, softly, gently, like he's done a thousand times before, and he tries to pretend that it feels the same. Like it's her and him, happy and in love and pure. But he can feel his brother there, feel the way the mattress dips under the added weight of a third person, feel the frenetic energy that always seems to emanate from Damon. He kisses Katherine harder, and she mewls her approval into his desperate mouth.

She shucks his pants off fluidly, then strokes him once, twice, before guiding him inside her. He sighs in relief as she takes him fully, her warmth a beacon in a stormy sea. This is right. He knows what to do.

She lifts her hips wantonly, and he begins to move, rehearsing the rhythm she taught him. It doesn't take long before he's panting into her shoulder, brow furrowed in concentration as he thrusts. He can feel his brother's eyes on him like a ray of sunlight, burning his skin. He speeds up his motions, drowning himself in Katherine's moans, Katherine's hair, Katherine's neck, KatherineKatherineKatherine –

Then his brother's hand is on the bare flesh of his back, a soft caress, barely there, and Stefan bows, his whole body arching violently, every muscle seizing in unbearable pleasure.

Katherine's eyes widen ever so slightly, but she smiles anyway, her lips curling in triumph. Stefan squeezes his eyes shut to block out the image of her knowing grin, and as he comes, he thinks he's never hated anyone this much.

\/\/\/

He wakes to the dull thud of flesh hitting wood, and he opens his eyes to see Damon pressing Katherine against the wall, fingers digging into the smooth skin of her arms. He hears his brother snarl, "Never again," his tone more pleading than he realizes. Katherine reaches up to stroke his face soothingly, and Stefan resolutely ignores the curious sinking feeling in his stomach. The new day has broken, patches of sunlight creeping across the worn hardwood floor. He closes his eyes again.

\/\/\/

The next time Katherine comes to him (not that night, but the next, that's his turn, there is a system), he begs her not to do it again. He starts to say "I don't want to share you," but the words catch in his throat, unwilling to be born into falsehood. Sharing her was never the problem. He chooses not to complete that thought.

It happens again, of course, and this time Damon can't hide the furious clench of his jaw, the rigid line of his shoulders. Stefan pretends not to notice – he avoids conflict when he can. He tells himself that's the only reason.

But Damon's anger remains, making his movements jerky as he rips his shirt off. Katherine sits back against the pillows languidly, unabashedly amused by his futile rage. Stefan perches awkwardly on the edge of the bed, wanting to help, not daring to interfere.

Damon gets to his knees on the bed, yanking Katherine roughly to him. She plays along, slinging her arms around his shoulders, meeting his lips for an open-mouthed kiss. Their teeth clack together, and Stefan's whole body jolts with the sound.

He stays there, rooted to the spot, for endless minutes, watching them. With the two of them right before his eyes, it's easy to pretend he hasn't been picturing this for days. Instead, he drinks it all in, this stolen view of his world condensed to one bed. The girl he loves, and Damon.

For a moment he thinks he's been forgotten, but then Katherine stretches her hand toward him, and he takes it automatically. She pulls him to the middle of the bed and casts her arms around his waist, her nails skittering under his shirt. She nuzzles his cheek, the gesture breathtakingly sweet, and Stefan allows her to pull his shirt over his head. He'll allow her anything.

The brush of her lips against his is feather-soft, innocent and tempting at the same time. She kisses him once, twice, thrice, again and again, each time a little deeper, a little hotter, until Stefan is leaning into her hungrily, striving to capture her mouth. She evades him, and he pushes, forward, forward, until suddenly –

She disappears, and he comes face to face with his brother. He gets caught in the blue of Damon's eyes, wide and shocked, for a vital instant, before swinging his head around to look for Katherine. She is back against the pillows, legs curled under her, watching intently. He gapes at her, but she smiles at him reassuringly. The briefest tilt of her head (an instruction, an order), and he's turning back to his brother.

For a moment they just stare at each other. He can see the scar on his brother's shoulder from when Stefan hit him with a rock when he was seven. He can see the delicate tracery of veins in his forearm. He is transfixed by the gentle bob of Damon's Adam's apple when he swallows.

Damon turns his head ever so slightly, his gaze falling to the space of bed between Stefan and Katherine. Stefan watches his brother's face, witnesses the play of thought whirling through his brain, observes the tiny nod of Damon's head, a confirmation. A promise.

Then Damon looks up and surges forward, connecting with his brother from knee to shoulder, plastering their bare chests together. He tangles his fingers in Stefan's hair, curving his other hand around the nape of his brother's neck. Meets his eyes, searches for something, finds it. And then he kisses him.

Later, Stefan would catalogue to memory the incredible softness of Damon's lips, the tugging of fingers in his hair bordering on pain, the searing heat of skin against skin. But at the first press of his brother's lips to his own, the florid words in his mind evaporate, leaving only sensation. Stefan opens his mouth against his brother's and moans like one of the damsels in the lurid dime novels Damon insists on keeping.

He is dimly aware of Katherine, still lounging against the pillows, but then even that is gone, replaced by the heady taste of his brother, the warm stroke of tongues, the deafening sound of gasps and groans and rustling sheets.

Katherine gazes at them raptly and thinks they're the most beautiful thing she's ever created.

\/\/\/

Stefan loses count of all the times after that.

\/\/\/

As Damon drinks from the compelled girl, sharpening teeth buried in her neck, Stefan keeps his hand on his brother's shoulder. He will never need to let go again.

The quarry is dark, the stars reflecting an otherworldly light on the still surface of the water. Damon drops the lifeless girl to the grass, tilting his head back in rapture as strength courses through him. The moonlight glints on the blood still streaking down Damon's chin, and Stefan dives for him, their mouths meeting easily.

There is no hesitation, only raw need, and power, so much power. Stefan clutches his brother, tastes blood and salt and eternity on his tongue, and thinks, This. This is right.

They tear at each other, fabric rending readily under hands thrumming with energy. Stefan rakes his nails down Damon's back, drawing red lines like strokes of paint. They heal instantly, the flesh weaving itself together before his eyes, and Stefan takes a moment to marvel that his brother will be this beautiful forever.

When it's over, they lie shoulder to shoulder, staring up into the night like they did when they were children mapping out the stars and their futures. The girl's bloodied body rests a few feet away, a crumpled heap of petticoats and broken vows. Stefan doesn't mind. She isn't their first audience. They are used to dead girls watching them.

There are a few moments in which Stefan is blissfully, utterly happy. He knows there are things he needs to process – his father's rejection, his first murder, Katherine's death, this new reality he's stumbled into. But for one breathtaking instant, he believes with absolute clarity that this is all he needs: him, his brother, and the open sky.

Then Damon is promising him an eternity of misery, and it all comes crashing down around him like the flimsy backdrop of a second-rate play. Stefan stands frozen, stunned, helpless, and in a flash, Damon is gone. The dead girl remains. Why is she still here? He thinks wildly, Why can't we ever just be alone?

He thinks of that first time, the nervous glances, the hesitation, the uncertainty. Wonders if Katherine would be proud of him now. After all, this is what she wanted. He thinks he understands now that this is what he wanted too.

He takes a deep breath, casting his eyes up. The sky is still there. He is still here. Damon is still here, in every way that counts. He's still here.

It might not be all he needs. But it's enough.

-fin