After we got home from the doctor’s office, I spent the rest of the afternoon watching television in the den. Liz chatted incessantly on the phone; I could have sworn she knew what had happened earlier at the doctor’s office but was too embarrassed to confront her. Mom was busy with some work, and since I didn’t want her to know that my left ear was getting achier, I tried to keep a low profile.

Porter arrived around 6pm as agreed, her baby bump clearly visible under her enlarged but still pert breasts. She and Mom spent about an hour huddled over the kitchen table chatting and planning the upcoming potluck. Since her husband was away on business and she only lived a few blocks away, Mom invited her to stay for dinner. The four of us had a meal of pasta that that Mom had quickly cooked up. My appetite was not that strong, and I started feeling chilly after we sat down, so ended up mostly just picking at my food. On the other hand, Mrs. Porter was actually quite charming, and I was reminded of why I had had a secret crush on her all these years. Even Liz was in a nice mood, her usual brattiness put aside for a while as she bantered with our guest. Despite the dull pain in my ear and chills, I was feeling pretty relaxed.

It was after the end of dinner when we were all about to get up from the table that my illusion of complacency proved misplaced.

“Luke, you remember Jill said we have to monitor your temperature,” Mom said in a rather ominous tone. It was a statement more than a question. I saw Liz’s eyes widen slightly as she anticipated what was coming. Even Mrs. Porter seemed to sit up a little straighter, the faintest tinge of pink creeping into her cheeks.

“I can see anyway that you’re not well,” Mom continued. “I’d better get the thermometer. Why don’t you go to your room and get ready. We’ll be right in.”

Having temporarily put out of my mind the events of earlier in the afternoon at the pediatrician’s office, I was a bit taken aback that Mom would so casually mention taking my temperature while Mrs. Porter was still there. That was especially true since the only reason I would have to go to my room and “get ready” was because she would be doing it in a way that required some privacy. Then it dawned on my what she meant by the word “we”. Liz got that smug look on her face that I remembered from our childhood after she had been switched to oral readings and I was still getting my temperature taken the “baby” way. I blushed and decided to resist.

“Mom, I’m 18. I think I can take my temperature by myself now,” I responded rather feebly.

Mom’s reaction was firm and a bit condescending.

“Don’t be silly, Luke. You acted childishly by going swimming despite your strep infection. That’s not the behavior of someone who seems ready to take responsibility for himself,” she chided. “Besides, I promised Julie that I would show her how to take a baby’s temperature. Since I obviously still need to use the rectal thermometer on you, I can demonstrate the technique for her at the same time.”

To say I was mortified would be the understatement of the year. My naïve daydream of somehow appearing grown-up to Mrs. Porter was shattered. Liz’s smug look had transformed into a smirk. Even Mrs. Porter was slightly more flushed despite (or maybe because of) having already seen me naked earlier in the day. All I could do was stammer and pretend to be angry, though in reality, my emotions were decidedly mixed, and my heart was racing.

After a few embarrassing moments of silence, the three of us headed upstairs. I looked back to see that Liz was still smirking as she started to clear the table. I went into my room and sat down on my bed to wait apprehensively while Mom and Mrs. Porter continued down the hall to the bathroom of the master suite.

They returned about a minute later. Mom was carrying two thermometer cases, a jar of Vaseline and a box of tissues. Mrs. Porter followed her in and thankfully shut the door, so at least Liz wouldn’t be able to spy. Mom opened the two cases and started her tutorial.

“The first thing to note is the difference in shapes,” Mom said to Mrs. Porter as she held up the two thermometers. “The long, slender tip is best for oral readings, since it provides maximum surface contact in the sublingual area. You can also use it under the arm, though the doctors all agree that is not very reliable, especially on children. The short, stubby bulb of the baby thermometer, on the other hand, can be inserted more comfortably into the patient’s rectum, so that’s the one we’ll be using today.”

My face reddened a shade.

Mom continued. “You can switch to the oral method once a child is old enough to hold the thermometer under his tongue and keep his mouth closed. But rectal readings are more accurate, even in older kids, so you should only change once they start putting up a fuss about privacy. Liz switched to oral at around 10, for example. Fortunately, Luke here has always been good about letting me continue to take it in his bottom!” she said with a smile, as if that was something I should have been proud of.

As I listened to her comparing me with my sister, I grew more and more embarrassed that I had not asked to switch to oral when Liz did. At the same time, my heart continued to race, and I felt a now somewhat familiar stirring in my loins as Mom described the benefits of staying with the rectal method. My arousal was exacerbated when I looked over at Mrs. Porter, with her baby bulge and swollen breasts, knowing that she would soon be looking at my bared and spread buttocks.

Mom went on to explain how to read the thermometer and shake it down to below 96 degrees, letting Mrs. Porter try it herself a few times to get the hang of it. She then put a thick glob of Vaseline on the tip, saying it would facilitate a more comfortable insertion. “It’s always better to have too much Vaseline than too little!”

To my embarrassment, the lecture then moved on to positions.

“For young babies, you can lay them on their back on the changing table and hold their legs up like you’re changing their diaper,” Mom went on to explain. Mrs. Porter reddened slightly and glanced quickly in my direction before refocusing her attention on Mom, who continued her lecture. “For toddlers, on the other hand, you get better control by laying them across your lap. Older kids can simply lie down on their side or stomach, but you can still do it over your lap if they won’t cooperate!” she finished in a slightly menacing tone.

That was the cue for the instruction that I had been dreading.

“OK, Luke, take your pants off and lie down,” Mom ordered matter-of-factly.

I stood and started to unbutton my trousers. Afraid of showing my now swollen penis, I decided to keep my briefs on. Mom was looking at the thermometer, but Mrs. Porter’s face reddened a bit as she noticed the bulge of my crotch before I was able to lie down. The two women sat down on either side of the bed, about at the level of my hips, which would give them both easy access to my rear end. Mrs. Porter’s bulging abdomen was just inches away from me, and I thought I could feel the heat radiating from her body. Mom handed the lubricated thermometer across to her and reached for the waistband of my briefs.

“We can’t very well take your temperature with these in the way!” she said in a tone that seemed halfway between joking and chastising me for not having taken them off before I lay down.

I raised my hips slightly as she tugged on the elastic and pulled the briefs down about halfway to my knees. Fortunately, they didn’t get snagged on my erection, but I did have to lift and move my hips a couple of times to get it comfortably repositioned underneath me. I hoped with all my might they didn’t notice, though something told me Mrs. Porter did.

My naked backside was now exposed to the two women’s gazes, and Mom pursued her tutorial, having arrived now at the most intimate part.

“You can use your thumb and index finger to spread his buttocks and expose his anus,” she said, still using her professorial tone.

I felt Mrs. Porter’s warm fingers slide down inside my crack and spread me open. I shuddered as the cool air touched my exposed anus, though I wasn’t sure whether it was from the cold, or the rather exquisite feeling of herhand as she accessed such a private part of my body.

“Next, you should gently insert the thermometer, aiming it toward his belly button,” Mom continued. “It should go in about half an inch for babies and toddlers, or one to two inches for bigger kids and adults. Stop if you feel any resistance.”

I shuddered again as the Vaseline touched my anus and I felt Mrs. Porter start to push the cold glass inside of me. She seemed somewhat tentative, a bit like Liz had been a few days before, and I thought I sensed a mild trembling of her hand. The feeling of the thermometer filling me up gave me a warm, tingling sensation, and I had to stifle a little moan of pleasure.

Mom took charge at that point, cupping my buttocks with her left hand and holding the thermometer firmly in place between her index and middle fingers. I had to budge a little bit, in order to reposition my now very hard penis. As I did so, I could feel the tip of the thermometer move inside me. I was ashamed but also somehow thrilled with both the physical sensations it created and the recognition that I was in a totally submissive situation.

Just then, we heard the phone ring, followed by Liz’s muffled voice. A few seconds later, Liz knocked at the door to my room then walked in without even waiting for an answer. She was obviously pleased to have a pretext to barge in and still wore that smarmy smirk. I caught her staring at the thermometer protruding from between Mom’s fingers before she spoke.

“Mom, it’s your colleague William on the phone,” she announced. “He says he’s finishing his memo this evening and needs your urgent input on some issue. Something about sales strategy.”

“Oh, I’d better take that,” Mom replied. She turned to address Mrs. Porter. “Julie, can you take over here? if I’m not back after 4 minutes, you should take it out and check it, then reinsert it for another minute to make sure it has finished registering.”

I felt Mrs. Porter’s hand as she placed her right palm on my butt and took hold of the thermometer. I must have turned another shade of red. Liz dawdled for a moment after Mom walked past her to take the phone call, most certainly to enjoy as much of the spectacle as possible. She finally exited, leaving Mrs. Porter and me alone. There was an awkward silence until Mrs. Porter spoke up.

“Thank you for letting your mom demonstrate this for me,” she said in a sweet, almost apologetic voice as she lightly caressed my back with her left hand. “I know it must be pretty embarrassing,” she continued. “But it’s really helpful for me. And don’t worry, I won’t tell anyone.”

I grunted something like “no problem”, and that I didn’t mind that much. I was too shy to say that I was really enjoying her company, and that the combination of the thermometer inside me and her warm hand holding it firmly in place were driving my 18-year-old hormones through the roof.

Then she added something odd: “At least I didn’t have to put you over my lap or take it in the diaper change position!”

I guessed she must have been joking. Still, I seemed to detect something else in her voice. Was it regret? Or maybe just wistfulness? I wasn’t sure. But the idea of lying on my back and having a pregnant Mrs. Porter insert a thermometer into my rectum while she looked me in the eye was suddenly and inexplicably extremely arousing.

My reverie was broken when she said, “OK, let’s go ahead and check it now.”

She gently pulled the thermometer out of my rectum, and I felt a vague sense of emptiness once it was gone. She wiped it with a tissue and held it up to the light to read it.

“Hmm,” she said in a slightly concerned tone. “Your temperature is almost 101. I’m not an expert, but I think that’s a little high. Your mom said it was 100.5 this afternoon at the pediatrician’s, and they already considered that a low-grade fever. Well, let’s see if it is finished.”

With that, she spread my cheeks once again and pushed the thermometer back inside me. Her movement this time was more confident, and I felt the glass move quickly deep inside before she cupped my buttocks once again.

Mom arrived back just as the extra minute was up and Mrs. Porter withdrew the thermometer a second time and held it up.

“I’m afraid it’s still a bit elevated,” she announced to Mom as she handed over the thermometer.

Mom had a look herself and frowned. “It usually goes up at the end of the afternoon, but this is definitely on the high side, even accounting for the daily fluctuation. I’ll take it again in the morning before work and call Jill to decide on a course of action.”

With that, she instructed me to get into bed as Mrs. Porter wished me a rapid recovery. In a way, I was not thrilled to be sick again, even if it was just a mild ear infection. Yet at the same time it was weirdly comforting to know that Mom would be back with the thermometer in the morning. I fell asleep with erotic thoughts of Mrs. Porter in my head.