He pulled out of her. She heard the snap of a plastic cap. She jumped slightly when the cool lube ran down the crack of her ass. She loved the feeling of her butt plug in her, but it was small compared to this mystery monster. She relaxed, allowing a well lubed finger to probe her anus. It was joined by a second and then a third. Stretching her, lubing her, it felt so good that she came again. She heard the snap of the cap again, followed by the sound of a plastic bottle hitting the shower floor. The tip of his penis, generously lubed, slowly entered her ass. She widened her stance to accommodate him, the hands were back on her hips guiding her. He starting fucking her, never pulling out, thrusting deeper with every stroke. She was cumming again, her warm juices trickling down her thighs. His pace increased, his grip tightened, and with a loud grunt and a final thrust he filled her ass with an explosive orgasm.
Without a word he withdrew his softening penis from her. No longer having the strength in her quivering legs to stand, she dropped to her knees. Her hands were still shackled to the wall bar, preventing her from collapsing on the shower floor. She was just about to risk opening her eyes when the water pressure returned. It was cool at first, but warmed quickly and she turned her face into the spray. She remained there allowing the water to wash the shampoo from her hair, face, and body. Finally, she opened her eyes. Hanging from the wall bar shower was a small key on a chain. She stood slowly, and released her hands from the cuffs. Now that her hands were free, she rinsed the shampoo from her completely. His cum was dribbling from her ass. She could feel the water washing it down her legs, she watched it swirl slowly down the drain in thick strings.
Finishing her shower, she noticed the bottle of lube on the shower floor. She picked it up, placing it in the top shelf of the shower caddy. Next she hung the handcuffs from the shower bar, next to the key. With a sensual smile of satisfaction, she stepped from the shower and wrapped herself in a towel.