Supply and Demand
She strokes her damp finger slowly up, touching her labia lightly, half because it feels so nice, and half because she loves for him to watch.
As her finger falls carelessly between the puffy folds, she lets it slide in, between her slippery walls, and deep inside herself. She does that for him, for his hard cock, for the sharp intake of breath.
The journey eventually continues. Her slippery arousal-coated finger of pleasure trawls across her waiting clit, glistening in the light from the street, and dragging a shadow of pleasure. This is hers. The rest was at least partially for show, but the clit is all for herself, for the tight clench of her muscles, the smooth cushioned rasp of her fingerprint bumping over her personal speedhump, for the deeply personal sudden spasm of pleasure, the gasp, the shudder, the stillness.
His respect for her private moment is indetectable, and as she comes so does he, spurting high in the air over the cheap motel sheets, grunting as his semen pumps recklessly from his hand-held member.
He throws a few dollars extra where she lies on the stained bed, and leaves without a word.
She can't help herself, and does it all again, for free.