Pairing: Kum, mentions of Klaine
Author's Note: Kum infidelity, basically. Inspired by this (-ladylips . tumblr .com/post/6047590651/ajjizom-vintage-gay-for-allison-spoiler (just take out the spaces)) video that came up on my dash.

Kurt isn't a saint, but he isn't a senseless whore, either.

He knows exactly what he's doing—he just plays the role of the naïve schoolboy to everyone's face.

Sam is the only one who knows of the double-role.

It started out as innocent. Kurt would go to Sam's and help him babysit his siblings. When they'd get tired and go to bed, typically that was Kurt's cue to leave—until, one night, Sam grabbed Kurt's arm with a suddenly vulnerable expression; that's when the word vomit came up and he unintentionally outed himself to his best friend (well, more like his only friend, at the time). Kurt was supportive, though, and made a promise to not out him. An invisible barrier seemed to have been broken down due to the revelation, though—neither of them felt awkward then they were in affectionate moods, neither of them walked on eggshells when the topic of romance came up, and Kurt didn't feel nearly as uncomfortable as he would've been when Sam asked for a backrub particularly intense football practices.

Sam did start to worry, though, when he noticed the butterflies in his stomach he'd get randomly around Kurt, and the way he couldn't help but smile constantly with him around, and when he found the countertenor at the forefront of his mind way too often to be considered normal. (This was when it suddenly wasn't so harmless anymore.)

Blaine has never exactly been the first thing Sam thought of when he was around Kurt (when he was brought up, though, Sam found himself with a headache from how hard he would clench his jaw). So the private school boy (Kurt's boyfriend) was definitely not in his thoughts at all (out of sight, out of mind) the night when Stevie and Stacy had long gone to bed, and Kurt was sitting on the couch with Sam, the both of them talking and their legs pressed against each other absent-mindedly and Kurt's hand rested on Sam's knee nonchalantly when suddenly Sam couldn't stand it anymore and he cut Kurt off mid-sentence to kiss him. Realizing what he did, he was going to pull back, but then Kurt was kissing him back aggressively as if he'd been impatiently waiting for Sam to grow a pair and do this already.

All of the build-up resulted in what they're doing now—Sam fucking Kurt into his own mattress (Carole's at work and Finn went with Burt to a football game).

This is a typical thing between them; they hang out, they fuck, they nap, and repeat. They don't ignore each other, because they're still best friends, but they fuck whenever Kurt gives Blaine a bullshit excuse that he believes anyway.

Blaine Anderson; Kurt doesn't think of his boyfriend once during his many moments of infidelity because honestly, Sam fucks him harder and better and his dick is bigger and holy shit that fucking mouth.

Sam always makes sure Kurt forgets Blaine's name because he can't fucking stand that dapper douchebag. He leaves marks on Kurt despite his half-assed protests (that he gave up even attempting to make), whether from gripping his hips so hard or sucking or biting on his skin, and he and Kurt both know that Blaine is either incredibly oblivious or he knows but believes the lies about how Kurt is so clumsy.

They've finished and Sam's arms always find themselves around Kurt's waist, holding the countertenor close as he toys with Sam's lemon hair or traces the tips of his fingers along his jawline and those swollen and bruised trouty lips.

Kurt's fingers are at the corners of Sam's mouth, poking the end of a finger in as Sam nibbles or sucks gently, and before Sam can even think about it he murmurs out a soft, "I love you."

Kurt doesn't freeze up or widen his eyes or say he has to go and hang out with Blaine the Dapper Boyfriend or say the words back to Sam. He continues ghosting his fingers over Sam's face, looking up at Sam's beautiful eyes and in any other situation Sam would've let out a quiet Lor menari. When they lock eyes, Kurt simply puts a tender, sweet kiss to Sam's lower lip, and it's in this moment that Sam realizes that although Kurt isn't thinking about Blaine, he's not exactly thinking about Sam, either.