I woke up late-morning the next day, having once again slept around the clock. My left ear was still aching. It didn’t seem to be worsening, but I still felt achy and chilly. My brain had a fuzzy recollection of Mom having come into my room earlier, pulled down my pyjama pants and taken my temperature as I lay on my stomach. It was strangely reminiscent of my young childhood, and that idea both embarrassed and excited me. The squish of Vaseline that I could feel as I walked downstairs confirmed that it hadn’t been a dream.

Liz greeted me in the kitchen with her usual smirk. While she did seem genuinely concerned, my 18-year-old twin sister couldn’t resist getting in a little dig that would have been worthy of a junior high schooler.

“How’s our sick little boy this morning?” she asked in a faux-sweet voice. “Mom said she had to use the baby thermometer again and that you still have a temperature.”

I blushed from embarrassment. It wasn’t exactly a secret that I was having my temperature taken rectally. Indeed, Liz had watched me have it taken (twice!) at the doctor’s office the previous week when I had my strep infection. She had even taken it herself here at home. Still, I was somewhat ashamed not to have insisted, like she had done before we were even teenagers, on switching to oral temps like an adult. Part of me wanted to grow up, but part of me also somehow wanted to still be cared for like a little boy. I couldn’t reconcile the conflicting emotions, so ended up acquiescing to (and even, dare I say, enjoying?) that most intimate of procedures. The price of my pleasure was a deep sense of humiliation at being treated like a child.

“I’ll be fine,” I said with a hint of irritation in my voice, pretending to find the whole thing distasteful. I don’t think I fooled her, but she dropped the subject and went into the den to read. I stayed in the kitchen and tried to distract myself with the morning newspaper.

A while later Katie stopped by and came right into the kitchen. Her face was slightly flushed, as if she had been running, even though she would have been coming from her house just next door. As usual, my heart started beating a bit faster at the sight of her. She was again wearing a sleeveless t-shirt without a bra, and her medium-sized breasts sagged slightly under their own weight, even as the nipples pointed straight ahead.

Katie had never been a conformist to traditional feminine tastes. Even though I was two years younger, I recalled that she had been a bit of a tomboy in high school and was more what I would call a natural girl, hanging out weekends at the beach with the surfer crowd rather than going shopping like most girls from our high school. And although her legs were shaved, she had tufts of hair under her arms, which seemed to proclaim her maturity and her independence from fashion norms. Seeing them that morning aroused strange feelings in me, and I felt my loins begin to stir. I also noticed that she had on a white skirt that came down to just above her knees. That was bizarre. I had never seen her in a skirt before and wondered what could have prompted her to wear one today. In any event, she was even cuter like that, so I didn’t want to ask any questions.

“Your mom asked me to come by and check in on you,” she said with a smile as she helped herself to a cup of coffee and came over to the table. “How are you feeling?” she asked while placing her hand on my forehead. She frowned slightly at what she felt then gently ran her hand down my cheek to my neck. It was a tender gesture that caused more stirring down below.

“By the way, where’s Liz?” Katie then asked. “I need to ask her something.”

I directed her to the den and ended up overhearing snippets of their conversation.

“I don’t know what those doltish brothers of ours were doing at the creek on Sunday,” Katie started in that rather disparaging tone that girls always seemed to use when talking about boys. “But Ben seems to have also got an ear infection plus a sore throat, and he was all flushed this morning. Mom and Dad are still up at the lake house, so I’ve had to play nurse and take care of him!”

I could just imagine Liz’s eyes widening slightly at this news and her leaning forward to listen more attentively as Katie continued. I was also intrigued to learn about what happened. Ben was just a month older than Liz and me, and it must have been ignominious to have to put up with a bossy 20-year-old big sister. But the story was even worse than that.

“He was obviously running a fever just like Luke, so I wanted to take his temperature,” Katie continued. There was a pause, and I figure the girls were probably smiling at each other. “But he kept coughing, so couldn’t keep the thermometer under his tongue. After three tries, I told him I needed to do it rectally. Honestly, he started acting like such a baby! He fought me the whole time. It’s not like I’ve never taken his temperature before! I finally ended up pulling him across my lap on the couch and giving his bare bottom a little swat to calm him down. Of course, once I inserted the thermometer, he became as pliant as a wet noodle. And his temperature was 101.2.”

I was a bit stunned to hear Katie telling Liz all that. I understood at that moment why she had been so confident the first time she had taken my temperature last week. The thought of my best friend lying over his big sister’s lap with a thermometer poking out of his butt was weirdly arousing.

“So, I need to ask a favor,” Katie continued to Liz in a slightly more hushed voice. “I’m going to be out for a few hours for aerobics class then an interview for a camp counsellor job. Can you pop in early afternoon to check in on him? The Tylenol should wear off by about 2:00. If his fever spikes, I’ll need to get him to the doctor.”

Liz didn’t hesitate even a second. “Sure, I’ll be glad to! I’m having lunch with some friends at the mall but will head over after that. Poor guy must be feeling miserable.”

“Great, thanks, Liz! I left the thermometer on the counter in my parents’ bathroom. Hopefully, he won’t give you any trouble.” I could sense the two girls’ smug looks of complicity.

After a while, Liz announced she was heading to lunch. I watched her go out the front door with a little smile on her face and a bit of a skip in her step.

That left Katie and me alone. My apprehension grew, together with my excitement, as I wasn’t sure what exactly I should do. I had never had a girlfriend before. Was Katie even my girlfriend? Should I try to kiss her? Or just play it cool? My mind was reeling with indecision. Fortunately, I didn’t really have to decide anything because Katie soon took charge.

“Let’s get you checked out, young man. I have a little surprise.”

She took me by the hand and led me upstairs. For some reason she brought her small purse up with her. My heart was racing.

Katie had me wait in my room while she went into the master bathroom, presumably to get the thermometer. It seemed like she was gone an eternity. When she finally came back, she had a kind of strange look on her face. She was carrying the familiar jar of Vaseline in one hand, and she had a towel draped over her arm. In her other hand she held a plastic case. It sort of looked like a thermometer case but was bigger. I noticed that her breasts were now visibly erect under her loose t-shirt.

Katie set down the Vaseline and spread the towel on edge of the bed. She then proceeded to open the plastic case. What she removed looked like a glass thermometer. But it was unlike any thermometer I had ever seen. The tip appeared about an inch and a half long and was shaped like that of an oral thermometer, with a long, silver bulb filled with mercury. Except that this bulb was as thick as the stubby bulb of Mom’s rectal thermometer. Then there was what you might call a shoulder, beyond which the glass widened. The rest of the instrument was thicker and longer. It was absolutely huge. I couldn’t stop staring at it.

“It’s a European thermometer,” Katie explained. “I bought it when I was in Paris last summer. It’s specially made for rectal use.”

As I stared, I found myself wondering why Katie would have bought a thermometer in Europe. Maybe she got sick during her travels? Then I started wondering exactly where this particular thermometer had been. That chain of thought led to even more pressure in my loins.

Katie sat down on the towel. As she did so, I noticed that she carefully lifted the back of her skirt, so that it bunched up behind her but continued to cover her lap in front. I stared at her creamy thighs, realizing now, to both my embarrassment and delight, that I would soon be lying across them.

She looked me in the eye and gave a simple command: “Strip.”

I was so flabbergasted that for a moment I was unable to move. I stood there wondering what to do.

“Take off all your clothes,” Katie again instructed. There was no ambiguity in her tone. It was not a suggestion or a request. It was an order. I slowly started to comply, starting with my socks, followed by my shirt and pants, which left me only in my briefs. As I again hesitated, Katie found it necessary to reiterate her instruction. “Everything,” was all she said.

I lowered my briefs to the ground and stepped out of them. My penis was by now visibly erect.

“Come here,” Katie instructed me next.

I slowly approached until my erect penis was just a few inches from her face. At that point, she seemed to hesitate for just a moment. Did I perceive a mild trembling? Maybe. But at that moment she overcame whatever reticence she may have had and pulled up the front of her skirt. I was expecting to see panties underneath, but to my amazement what appeared instead was a triangular-shaped mass of thick pubic hair. I had never seen a naked woman in real life and was mesmerised by the sight. Katie spread her legs slightly to reveal her dark bush in all its splendor She took my hand and guided me to lie down, pushing my erect penis between her thighs. Once I was settled, she slowly closed her legs together. The effect was to squeeze my membrane and pull it up against her warm crotch. I was, for all intents and purposes, held captive, although not in the least against my free will.

“Now, it’s time to take your temperature,” Katie said in barely a whisper.

She opened the jar of Vaseline. Instead of putting the thermometer in, she used her right index finger to scoop up a dollop of the gooey gel. With her left hand, she spread my buttocks apart and spent a long moment just staring at my exposed backside from up close. Then she started rubbing the Vaseline on me, moving around my anus in tighter concentric circles until she reached the destination and plunged her finger inside, up to what I suppose was the first knuckle. The feeling was exquisite, and I felt compelled to squeeze her finger as tightly as I could. That elicited a soft giggle.

After removing her finger, Katie next picked up the European thermometer. I was somewhat apprehensive about being penetrated by something so big, but her confident manner reassured me. She started to push the instrument inside. At first, it felt just like a normal thermometer, and I started to relax. But then the “shoulder” pressed against my anus, and I felt a torrent of sensations and emotions that I cannot even describe. Katie maintained pressure on the thermometer, and my anus finally gave way. The long instrument slipped deep inside, filling me up in a way that I had never experienced before.

“There, how does that feel?” Katie asked in a hoarse voice. Something told me that she knew exactly what it felt like. I could only croak out some unintelligible response.

Next came something that set in motion a cascade of overwhelming events. Katie started gently moving the thermometer in and out of my rectum, while continuing to use her thighs to squeeze my erect penis and pull it against her now moist bush. The sensations became irresistible, and I started to move my hips in rhythm with her in-and-out motions. The effect was predictable, and I was finding it more and more difficult to contain myself.

“Katie,” I croaked while she continued her movements. “I think I’m going to….”

“Ssshhh,” she quickly interrupted in a soft voice. “Just let it happen.”

I didn’t need any more encouragement than that. My penis exploded, sending a stream of hot liquid between Katie’s legs and onto the towel below. I had masturbated before, of course, but this was the first time I had experienced an “assisted” ejaculation. The experience was in a league of its own.

I started to slow the movement of my hips, but Katie immediately spoke up.

“Don’t stop!” she ordered, her voice even huskier than before.

As I continued my now slightly feeble gyrations, Katie reached up with her left hand and caressed her breast. The sight of that made me start to get hard again. After a few moments, I felt a slight shudder underneath me. Katie let out a soft wheezing sound then fell still.

We lay there for a few minutes, neither one of us wanting to interrupt the intimacy of the moment. Finally, Katie snapped out of her reverie.

“Shall we check that temperature now?” she asked in a voice that almost seemed back to normal.

She pulled the thermometer from my rectum and wiped it with a tissue, while still holding my now flaccid and sticky penis between her legs.

“Hmmm. Almost 39 degrees. I’ll have to convert it, but that seems a bit high still. We’d better re-check it after you’ve calmed down a bit!”

Once I had got up, Katie helped to clean me up, gently fondling my manhood as she used the towel to remove the mess. She then wiped between her own legs and let the skirt fall back into place. There remained no outward sign of our amorous activity.

“Lie down and rest,” she ordered. “I’ll be back in 20 minutes to check it again. Then I’ll call your Mom to see if you need to go to the doctor.” She hesitated a moment before continuing. “Shall we keep this our little secret?”

I nodded meekly, not knowing what else to say. Katie left me lying naked on my bed, and I drifted off to sleep.