He tastes like pain. Gaara can't help but register the distinct flavor of old blood and the scent of disease and sawdust heavy on his older brother's skin (-and such as it is, he would never forget something so distinct as that, something thick in the air, the remnants of what they have in common-) and their kisses are hard, a mashing of lips, only somewhat awkward, because Gaara learns quickly and their father taught Kankurou well.
And there is anger and demand in the demon's throbbing lust, teeth ripping lips apart, sweat pooling with the tears, clotted red between teeth, blood mixing in with come, sweat, tearing Kankurou apart piece by (-But that is only Gaara's demon. He will never be completely sane, but the part of him that could have been remains somewhat-) unforgiving piece. And it is this side of him that Kankurou fucks, a sex almost silent and driven by nothing but unapologetic incestuous lust.
(Because Gaara is not a lover, he is a demon, and Kankurou is too far gone at this point, and they used to hope Temari would save them, but in the end-)
Maybe they are both crazy.
(-They could never be saved.)