Sasuke knew he was never one to have love. His life consisted of killing Itachi and perhaps reviving his clan (if he didn't die first, not that he particularly cared). So when he fell in love with Naruto he knew it wasn't right, because love and Sasuke just don't belong in the same sentence unless there's a 'can never have' in between.
Naruto doesn't love him.
But Sasuke loves Naruto, or maybe it should be 'loves' because Sasuke doesn't know what love is anymore. Sometimes he imagines Itachi tearing out his heart and destroying it, but that's only when he's half-drunk and half-insane and half-dying because Sasuke doesn't have much of an imagination either.
Sasuke always gets what he wants.
He wants Naruto, but Naruto doesn't want him. Still, that doesn't stop him and he tries to convince himself that all love is right and moral even as he's tying Naruto to a bed and fucking him despite the blood and the tears and the dreadful pleas just to stop because it hurts.
In the end, Sasuke gets tired of Naruto's broken sobs and gags him, stroking his face with a gentle tenderness even as he pounds relentlessly into the shattered body of his 'love'.
Sasuke never was one to have love, but this twisted version of it is enough for him.
A/N: Don't know what the hell I was thinking of when I wrote this, but I wanted to do an insane Sasuke story… Review?