In the dim glow of the gas station's fluorescent lights, a brother and sister stand, their bodies pressed close as they wait for their car to be fixed. Their eyes meet, and the air between them crackles with unspoken tension. She bites her lip, her gaze flicking to the restroom, and he nods, understanding her silent invitation. They slip inside, the door clicking shut behind them. He pins her against the wall, his hands roaming her body, cupping her breasts, squeezing her ass. She grinds against him, feeling his hard cock through his jeans. He unzips, releasing his length, and she wraps her hand around him, stroking him, her thumb swirling over the head. He growls, lifting her up, and she wraps her legs around him as he thrusts into her, fucking her hard and fast, their bodies slapping together, their moans echoing in the small, tiled room.