He won’t tell him he’s been a bad boy because that’s what he wants to hear. But he spills him over his lap, elevating his plump cushy ass, and spanks him like he wants to be punished. This is Karkat’s penance he chooses for himself, burning with shame fueled by guilty desire as he lays prone over Kankri’s knees, heat suffusing both sets of cheeks as a bare hand comes down again and again on his backside. The thin red fabric of his boxer briefs not only supplies tenuous padding against the blows, but acts as a substantial warm-up.
Kankri says nothing as his palm rebounds off the clothed derriere, all of his mental faculties centered on focusing his aim, swift and precise. Karkat’s throaty moans assure him he is not missing the mark. He can feel Karkat’s body twitching as therapeutic spanking crosses the threshold into lust-driven delirium. He pauses, sweeps a hand affectionately over Karkat’s mussed hair, and peels the undies back, exposing each deliciously pink globe. Karkat tenses, feeling the fabric bunch up between his cheeks, and swallows a moan as his dancestor’s hand cups one, then the other, the pinch of nails into the underside unfairly titillating.
He comes to Kankri because he hates him unlike anyone else he’s ever hated. In that hatred he also trusts him, trusts that Kankri—unrequited kismesis or not—will push him to the limits of his rage.
And he does, diligently slapping those naked ass cheeks until he notices the crotch of the little red undies dampening. Arching a brow, Kankri runs his thumb over the wet spot, pressing just a bit too firmly into the soft yielding dip concealed within the cloth stretched over Karkat’s saturated nook.
Karkat mewls, juts his throbbing ass out, entreating; Kankri ignores Karkat’s unspoken demand, patronizingly patting his rump instead.
Kankri smirks surreptitiously at Karkat’s red, raw ass.
“Not nearly as much as you hate yourself.”
Karkat’s groan turns shrill when a thumb worms past the stressed fabric and penetrates his nook, a single finger triggering a humiliatingly violent orgasm.