[Editorial note: This chapter picks up after the end of Chapter 12 of “My Memorable Fever”, a parallel companion story involving the same characters.]

Ben was still processing the tumultuous emotions from the events of the past 24 hours as he lay in his bed reliving the experiences. He was not happy to be sick, of course, especially since he had obviously caught his best friend Luke’s nasty strain of strep and felt miserable. He was also positively terrified at the idea of having to go back to the doctor and get another shot, a phobia he had had since childhood, and which proved totally justified based on the pain of the previous day’s antibiotics injection. On the other hand, he didn’t necessarily mind having his older sister Katie take care of him, just like she had always done since their mother had restarted working when he was 8 years old. When Katie insisted on treating him like a baby the previous morning and taking his temperature over her lap the way she used to, he put up a little fight out of principle but was also somehow weirdly happy to have her in charge again. It reminded him of when they had played doctor together as children (and even occasionally later), and Katie would always insist on being the nurse. Especially given his current state, it was easy for him just to let her take charge and enjoy her ministrations. The feelings were strangely erotic and yet non-sexual at the same time, and Ben wasn’t sure exactly how to deal with them.

Things had become even more complicated later in the day, when Katie invited Luke’s 18-year-old twin sister Liz to fill in with his care while she was out at job interviews. Although the three of them had all been friends and classmates for most of their lives, Ben had only recently noticed what a beautiful woman Liz had become. He took a special interest in her slightly saggy but pert breasts, which had bounced erotically underneath her partially transparent tank top when she had come over the previous day. But what really got his mind reeling was the way in which she took charge, re-taking his temperature in his rectum before arranging an appointment at Village Pediatrics. It was at Village Peds that Ben was humiliated, and yet somehow oddly aroused, by Liz and their fellow former classmate Debra Hobbs. The two women had been best friends for as long as he could remember, and their quiet complicity in his treatment at the doctor’s office added an extra layer of potency to his embarrassment.

The icing on the cake had come at the end of the day. After dinner, Liz insisted that he get totally naked in front of her in the den. He had somehow felt powerless to resist her commands as she lay him across her lap just as Katie had done earlier and took his temperature again with the rectal thermometer. His erection was so hard at that point that he felt he might ejaculate right then and there between her warm legs. But then it got worse. Liz proceeded to administer a suppository, moving her warm finger in and out of his anus several times as if she were teasing him. As soon as she had finished, he ran naked to the privacy of his room and exploded before he could even shut the door, ashamed and relieved in equal shares.

Now, he was trying to sort out all the conflicting feelings generated by those events. First and foremost, he felt betrayed by his big sister. For most of the last 10 years, Katie had always taken care of him when he was sick, and he felt a bond of trust and complicity with her. The fact that she had not only told Liz about how she still used the baby thermometer to take his temperature and invited Liz to do the same was bad enough. But then, to top it off, Katie went next door and devoted her ministrations to Luke. The fact that she was also taking Luke’s temperature rectally seemed like a slap in the face, and he felt an inexplicable pang of jealousy. He knew intellectually that it was silly, but he couldn’t shake it.

And toward Liz, his feelings were even more complex. He couldn’t deny the newfound sexual attraction. She was beautiful in a natural way, with a fit body and, like his sister, a confident display of body hair (even though, because she was blonde, it was more discreet). And the way she took charge of him was amazingly erotic. At the same time, he did resent her, both for taking his sister’s place as his caregiver and for treating him like a little boy. As it turns out, though, he was about to get vengeance of a sort.

When Liz came back shortly before lunch, it was the first time he’d seen her since running back to his bedroom the evening before, and he was a bit apprehensive. Did she know he had ejaculated? Would she mock him? As it turns out, he needn’t have worried. She was still radiant when she appeared in his room holding an already lubricated thermometer, but she didn’t say much. Her face had taken on a pallid hue, and there was a certain listlessness to her movements. Even when she insisted on taking his temperature (fortunately, he was still in bed, so she didn’t even try to get him across her lap again), she seemed distracted and barely talked as the thermometer registered, held between her fingers.

Katie came home from her latest interview just when Liz was about to remove the thermometer from Ben’s bare behind. The two women briefly exchanged “patient” updates as Ben lay there naked, before turning their attention to his thermometer, which fortunately showed a slight decrease in his fever. It was then that Katie noticed something was wrong.

“Are you feeling all right?” she asked Liz, a concerned tone having crept into her voice.

“Yeah, I’m fine. Just a bit tired, I guess, and I do have a bit of a headache,” Liz replied weakly.

Katie put her hand on Liz’s forehead and gave one of those motherly frowns that Ben recognised so well from his own experience. “You took terrible, and you feel warm yourself. I hope you didn’t catch what these boys have been passing around. Why don’t you go lie down on my bed. I’ll be in after I finish up with Ben.”

Liz didn’t need to be told twice. She immediately departed, leaving Ben alone with his sister. There was a brief moment of silence as the siblings contemplated the unusual situation. Katie seemed to be smiling. Was she making fun of him as he lay there naked? He couldn’t be sure. Before he realised what was happening, Katie picked up a suppository from the nightstand and unwrapped it. For the second time in 10 minutes his bottom was spread and he felt himself penetrated. Once she was sure that the medicine was deep enough, Katie withdrew her finger. She pulled up the bedsheets to give him some privacy and gave him a friendly kiss on his forehead.

“No peeking!” she admonished him with a wink and a mock finger-wagging before leaving his room.

Ben could hear his sister rummaging briefly in their shared bathroom as he pondered what she meant. Before long, she walked down the hall to her bedroom. Unable to contain his curiosity, Ben immediately got out of bed despite his aches, donned his bathrobe and ventured down the hall. Katie had left the door to her room ajar, giving him an unfettered view of her bed from the shadow of the darkened hallway. What he saw astounded him.

Liz was sprawled on the cushions and watched with a pale face as Katie sat on the other side of the bed and shook down the European thermometer she had bought in Paris the year before. Ben felt twinge of arousal as he remembered the time Katie had used that thermometer on him; the thick stem pressing against his anus as his sister had held the instrument firmly in place had caused him to get an embarrassing erection. Later, when he was home alone, he would sometimes sneak into their bathroom, retrieve the large instrument from its hiding place behind Katie’s makeup and pretend that she was using it again on him. It was Katie’s soft voice from the bedroom that roused him from his reverie.

“We shouldn’t use this orally, given where it has been,” Katie was explaining to Liz. “So, let’s try taking it under your arm. It might not work, but it’s worth a try. You’ll need to take off your top.”

Ben watched in stunned silence as Liz removed her pink polo shirt, revealing her slightly sagging and freckled breasts and the tufts of blonde hair in her armpits. As she plopped back down on the pillows, now naked from the waist up, her breasts flattened out and fell slightly to each side of her chest. The nipples in the middle of her large areolae were fully erect and resembled pencil erasers. Katie placed the thermometer in the middle of the hair in Liz’s left armpit and gently pulled her arm across her torso to hold it in place. She then gently caressed her neighbor’s cheek, before sliding her hand down until it came to rest on her Liz’s right breast. Liz’s face had regained a semblance of pink color as she stared up at Katie.

After a few minutes, Katie retrieved the thermometer and again gave her “mother” frown.

“This has barely registered,” she announced. She then continued in a soft, almost seductive voice. “It seems that someone has too much hair under her arms! I’m going to need to do it another way. Do you trust me?”

Liz’s eyes grew wide as she understood the implications of Katie’s question, and her face seemed to flush another shade of pink. But she quickly nodded her assent. Katie set down the thermometer, undid the button and zipper of Liz’s jeans, helped her to raise her hips, and slid the garment down her legs and off. Was it Ben’s imagination, or did Katie then glance up at the door and flash him a brief smile? He couldn’t be sure, but it sure seemed like it. To his amazement, Katie then turned back to Liz, took hold of her white panties and slid them off in the same manner, revealing the thick blonde triangle of her bush.

Katie picked up the thermometer then gently pushed Liz’s legs apart to expose the slit of her vagina, which now glistened in the sunlight coming in through the window. As Liz’s legs got pushed further apart, her pink anus appeared among the tufts of soft hair.

Katie lowered her voice to a whisper. “Fortunately, we girls don’t need to use Vaseline!” she cooed with a slightly mischievous smile.

With that, she caressed Liz’s slit up and down then slipped two fingers briefly inside. After a bit of massaging, she removed her fingers and rubbed some of the moisture onto the thermometer. She placed the tip against Liz’s anus. Liz jumped slightly as the cool glass first penetrated her, then moaned as it slipped inside, and the thick shoulder of the instrument pressed against her tight orifice. The two women stared at each other with strange expressions on their faces until Katie broke the silence.

“Further?” she asked in a soft whisper.

Liz’s eyes grew even wider, but she again nodded her assent. She whimpered as Katie put more pressure on the thermometer, and the thick part of the stem slid deep inside, disappearing from Ben’s view. Liz then started to slowly gyrate her hips and moan as Katie held the thick thermometer firmly in place. Liz closed her eyes, and her hands moved seemingly involuntarily up to her own breasts, where they began caressing her hard nipples. After about a minute, Liz opened her eyes, turned her head and looked directly at Ben. Was she surprised to see him? Would she be angry that he was eavesdropping? It didn’t seem like it. Her breathing grew shallow as she continued to stare at him and caress her breasts. Finally, she let out a muted scream. Her whole body seemed to contract, then relax, and she slumped panting back on the pillows.

Katie was also blushing as she retained the grip on the thermometer protruding from Liz’s exposed and now wet anus. After a few minutes, she finally pulled it out and held it up to read the temperature.

“38.6 degrees Celsius,” she announced with a slightly shaky voice as Ben continued to stare dumbfounded. “It looks like we have a new patient.”