"Nurse, bring the oil," Cathy said. "Okay, Mr. Porter could you roll to your side for me?"
Danny did so, his hard cock pointing off the side of the bed, where Cathy knelt to bring her mouth level with it.
"Okay, nurse, please take the patient's temperature."
"What?" Elaine was still thinking of the heat of Danny's cock in her mouth and remembering what his cum had tasted like. "What?" she repeated.
"Please take the patient's temperature anally," Cathy commanded.
Elaine had forgotten about that. As kids loved to play with butts.
She climbed onto the bed behind her brother and poured oil on her finger. Cathy was looking up at her past Danny's hip, smiling with pure lust in her eyes as she reached over and pulled up on Danny's buttock.
Elaine looked at her brother's puckered asshole a moment and then pointed her index finger and touched it. It contracted and his dick twitched. She moved her finger around it, lubricating the area, and then pressed inward. It resisted at first, but she continued the pressure until the tip of her finger entered him. Danny sighed, Cathy grinned, and Elaine pushed her finger all the way in.
His ass was hot, and Elaine wondered if that was how her pussy might feel on his cock.
"Boy, look how hard he got!" Cathy said, and Elaine could see that his cock was harder now, with the veins standing out on it. "Can you get two fingers in there?"
Elaine used more lubricant and then pulled one finger nearly out and slipped her second finger in with the first. Danny gasped, mouth hanging open. "Fuck his butt with your fingers," Cathy said, and then she put her mouth back on his cock and began sucking him hard and fast.
Elaine did as she was told heedless of how strange the whole thing seemed to her. Then she smiled, thinking of something even better. "I've got a tool," she said. She leaned up and fumbled under her pillow to bring her pink vibrator out and show her friend.
"How was his temperature?" Cathy asked.
"He's quite hot."
"All right then, apply the tool."
Elaine lubricated the vibrator and pressed it against Danny's asshole. She switched it on and turned it as pressed it into her brother's body.
"Holy shit!" Danny said as Elaine moved it deeper inside.
Cathy pushed Danny's top leg up and leaned her head in to suck his balls, her nose touching the vibrating tool in Danny's ass. She sucked his sack and stroked him almost to the point of no return and then stopped.
"That's enough, nurse. We mustn't over stimulate the patient. You may take the tool and wash it while I test the patient's tongue coordination.
When Elaine returned from her task, Cathy was squatting over Danny's face and he was happily lapping and sucking at her pussy. Cathy looked directly into Elaine's eyes as Danny sucked on her clit, so Elaine could see the twisting expression that over came her when his tongue brought her to a small orgasm. "Oh, my," she sighed, smiling at Elaine. "Very good."
Cathy hopped off of Danny's face, his cheeks glistening from her juices, and moved around to straddle his hips. "Hold it straight," she said, and Elaine jumped to obey without question.
She grasped Danny's cock, holding him up as her friend lowered herself down onto it and began humping him. When Elaine withdrew her hand, Cathy grabbed it and pulled it back, placing her fingertips onto her own clit.
"Could you please hold that little button down for me?" Cathy said, her eyes hooded with lust. "Be a good little nurse and hold my button."
Elaine did so, moving behind her friend so that she could keep her fingers in place more easily. She parted slipped her fingers down, feeling Danny's cock sliding in and out, and then back up to rub Cathy's clit for her as she placed her other hand on Cathy's shoulder to steady herself.
Danny was staring at her fingers on Cathy's clit. His eyes opened wider still when the girl riding his cock turned her head and kissed his sister on the lips. Elaine returned the kiss, inserting her tongue into her friend's mouth.
"Ah, ah, ah," Cathy threw her head back, cumming so hard that she fell to her side on the bed, her gaping pussy exposed to patient and nurse alike.
"Test your hip reflexes now, Mr. Porter," Cathy gasped. "Hurry."
Danny scurried around and lifted Cathy's legs up and over his shoulder as his sister moved around to get a good view. He pressed his cock down, finding the opening, and dropped his body down to slam into Cathy's hot cunt.
Cathy screamed once and then clenched her teeth, thrashing, gasping, and cumming like mad. Her pussy contracted on Danny's cock, milking him, bringing him to his own grunting orgasm. He spurted once into her pussy and then pulled out, spewing a shot that hit Cathy's chest and another tracing a line over her stomach. Finally, he lay beside his doctor, totally spent.
"Clean me up, Nurse," Cathy said breathlessly. "Tell me if he still tastes healthy."
Elaine only hesitated a moment before leaning to suck her brother's cum up off of Cathy's hot skin. She licked down her stomach and slurped the cum that pooled in her belly button, the smell of Cathy's overheated cunt filling her head. She fondled her own pussy as she completed her task, trembling against her hand.
"Now clean up the patient," Cathy said.
Again, Elaine's hesitation was only a split second. She knelt over her brother and took his cock into her mouth. Now she could taste Cathy as well as him. Now she was really too far gone to stop at anything. And Danny's cock grew hard in her mouth, nearly as firm as it had been at the beginning. Elaine was concentrating so hard on her pleasant task that she didn't notice Cathy get up and move behind her until she felt her friend's hand slip between her legs to cup her pussy.
"You're wet," Cathy said, sliding two fingers into her. "Hot."
Elaine arched back, still holding her brother's cock but wanting to feel more of her friend's moving fingers. Danny lay on the bed watching his sister lift up, her head moving back beside Cathy's head as Cathy moved three fingers in and out of her sopping pussy