I awoke with a start that Sunday morning, not really sure what time of day it was (thankfully, I was off work on Sundays). I weirdly felt that wasn't alone, even though my wife of three years had just gone back to visit my in-laws in Colorado for the summer. So far, despite a growing sense that I blundered into monogamy when I knew better, I had behaved myself, too. I had kept my vows, made largely to placate her. It wasn't through fear of financial ruin, either, as both of us were teachers, so were not doing that greatly.
We weren't financially hamstrung too much, but it did hurt our bottom line a little that Sandra had taken a trip to visit the folks instead of taking on a summer job as she had done in the past...and as I did every summer as well. Generally speaking, the summer job paid better than either my salary or hers, and we were both tenured! I usually taught typewriting classes to young secretaries and my wife mostly taught summer swimming lessons. At any rate, this was my situation, and I was just glad that I had my summer job to help pay bills and allow for a few luxuries.
I was more than a little stunned when, in addition to the presence of someone else in my home, I smelled something...familiar. It followed the scent to my dick, and I touched it, feeling what could only be the juices of a woman on my prick. That made it clear. I wasn't just feeling things. This was tangible, olfactory evidence that I wasn't alone in my house. Rising from my bed, in my haste forgetting to cover up (why was I naked in bed, either, as I usually didn't bother with that unless Sandra and I got it on), I followed what appeared to be a path of clothes leading me to the kitchen.
There, to my utter and absolute shock, was my sister-in-law, Kelly. She was very naked and very beautiful, but she looked a bit hassled or tired, at least in terms of the dark circles under her eyes that shouldn't belong to a newlywed bride of just twenty-three. She was naked as well, and I could smell cum on her, MY cum I realized with another jolt, proof positive that I had slipped from my vows and slept with not just another woman, but my wife's sister! Furthermore, she was another man's wife, so I had put horns on her husband, which was an additional rude awakening to me.
"Um...Kelly?" I spoke aloud, causing her to turn her head.
"Not yet, please, Robert. I know that you'll want an explanation for this, but not quite yet. It's a fait accomplis, anyway, now, isn't it? The dirty deed is done," Kelly assured me, "Now, please, let me cook breakfast for my summer hubby."
"Summer hubby? Or is that hobby?" I joked a little, to ease the tension, and it worked, making Kelly laugh softly at my jab.
"You'll see," Kelly told me, "I'm almost done, in fact. Sandra made me promise to rise and cook breakfast for you every day that I'm here, in addition to making sweet love to you. Not that it was hard to agree to either of those two things."
"What about Jimmy, you know...your actual husband? What does he think of all of this?" I was a bit shaken up by now, knowing that Sandra had connived with her sister to have a substitute wife planted in our bed and kitchen.
"We'll get to that, baby," Kelly promised me, "Please let me focus on this task for just another moment. I know that we women are supposed to be great multi-taskers, but even we have limits, and this topic is going to require more than enough focus to cause me to burn your breakfast, which would suck since I'm hungry, too."
"Fair enough, dear. Wait, did I actually...?" I stopped short, realizing that I had used an endearment toward my sister-in-law as freely and naturally as she had done toward me.
"It's okay, honey. You'll get used to it. I know that I could easily grow accustomed to such expressions of affection myself, at least with you, that is. I've always enjoyed hearing such terms frequently thrown around by a couple very much in love. You were never shy about that, were you two? It's inspiring, honestly. Don't let your first act of infidelity make you feel otherwise. You're an amazing husband. Sandra's always bragged on you, how great you are with her. By the way, she's pregnant," Kelly told me as she finally plated our morning meal.
"She's...pregnant? She hasn't told me that," I commented with shock.
"It's my job to deliver the news, baby. You'll understand very soon. Don't worry, it's definitely yours. Sandra hasn't messed around on you. In fact, she has resisted the family tradition, very much so. Until now. Three years. That's what she asked for, and that's what she got. Three years, until she was ready to fall pregnant. Once she had your baby safely in her, then she could handpick her substitute and you could select yours," Kelly only confused me further with that remark.
"Substitute? Wait, I thought that Sandra wanted me all to herself. She told me that repeatedly, got very jealous at times of other women, all that jazz. You mean that was only supposed to be temporary? I mean, she convinced me to marry her, swear off other women, everything, all for it to just be for three years? It doesn't make sense!" I exclaimed with astonishment.
"Actually, if you recall, your vows never included the words, 'forsaking all others,' did they? Think back to your wedding. Did you ever once say those words, even in rehearsal?" Kelly reminded me, "Did I at my wedding to Jimmy? Did he?"
That jogged my memory, and sure enough, those words were a curious omission that occurred to me at the time. I put it down as implied and reminded myself that there were many variations of the traditional vows. I didn't think anything further of it, but there were also jokes that were hard to explain in hindsight, which I just dismissed as mere bawdy humor. The one that stuck out most was when my father-in-law teased me about signing my life away, "for the next few years away." That was a curious statement, as was my mother-in-law telling me, "I look forward to seeing more of you in the few years."
As the light dawned on me, I saw Kelly's face change and, "Yes, he's catching up to us," pop up on her face.