Amon had a hundred reasons to want Robin dead, and no right to desire her.
He looked at the graceful column of her neck, and thought of leaving marks against her skin. He refused to look, would not, could not, and the sight of Robin's subtle curves was burned against the inside of his eyelids. Nighttime, and Robin sleeping in the bed across from his, Amon imagined the slide of her skirt against his cock as she moved to straddle him. He left evidence of his frustration and want in the curve of his arm.
He thought that it would be easier to bear the weight of Robin's death than live with the want of her.