An Unexpected Summer

Authors Note: This is the first of two different endings to the series (at least for now). This is admittedly not the original ending I had planned, and in my opinion, it sort of stretches believability around the established characters. But an early reader suggested doing alternate endings, this one immediately came (no pun intended) to mind nearly fully formed, and seemed fun enough, so I wrote it out. :)

Enjoy.

—

As I helped unload the groceries, there was only one thought in my mind:

I had to tell Jessica.

It was as simple as that. It was awful, but that's all there was to it. I knew she'd be furious. But if I didn't tell her first, Summer might. Maybe Jessica would break up with me, or just want me to go home. Honestly, at this point, either would be fine with me. Anything was better than constantly lying to her, constantly being teased into further cheating by Summer.

I didn't trust myself anymore. And with Summer pissed, even if she didn't tell Jessica, I was worried that she'd do...

something

. Who knew what.

Better to tell Jessica now, and face the fallout -- whatever it was -- than to have Summer tell her. Or, worse, to have Summer arrange things so that Jessica opened the door to our bedroom on evening to see Summer riding me, or something.

So I took a deep breath, and asked Jessica to go on a walk with me.

—

"I--I can't believe

that's

what's been going on..." she said the words, brokenly. She had cried, at first. We had been walking for about half an hour. I had deliberately kept us walking away from the house -- so that if Summer came after us to interrupt this, she wouldn't find us any time soon.

"I'm so sorry, babe." The guilt swelled in me. "I...I didn't know what to do after she started making moves on me, I didn't want it to upset you, so I didn't say anything, but she just kept doing it, and, and..." I shrugged, helplessly. "I'm sorry. I should've told you right away."

She nodded, still sniffling. "I--I'm glad you told me. To be honest...I'm mad at you...but I'm even angrier at

Summer

." She spat her name out. She looked at me directly. "You're...being totally honest with me? She initiated everything?"

I nodded, vehemently. I had told Jessica about each encounter. "I swear, babe. I...well, look, I'm not blameless. I could've done more to resist. And I should've told you right away. But I haven't been chasing her. I just want it to stop." I was relieved to be telling her. It felt good to come clean.

She was speaking quietly now, with a strange intensity, for Jessica. "I knew something was going on. I could tell she was lusting after you. God, I'm such an idiot. I thought her crush on you was cute, it was fun to fantasize about how quickly you'd make her cum...she must've been thinking the same thing...god, the way she's been complaining about college boys, and with how good you are in bed, it's no wonder she's been after you nonstop..."

...So maybe I hadn't been totally honest about

every

little detail. I hadn't

lied

, but Jessica had made some...major assumptions about Summer's satisfaction with my performance. And I hadn't corrected them.

But can you blame me? What was I going to do, give her the details? Tell her that her sister was fucking amazing in bed? Tell her about how fast Summer made me cum? That I couldn't handle her? That I hadn't even ever made her orgasm? None of that was going to make Jessica feel better about the situation. None of it felt as important as the basic betrayal I had committed, anyway.

I put those thoughts out of my mind, carefully not addressing the premise of Jessica's comments. "I know, babe. I'm so sorry. What do you want to do now? It'll obviously never happen again. Do you want me to leave? I-I'll do whatever you like...I understand if you want to break up..."

She hesitated, then slowly shook her head. "I...I don't know. No, I don't want you to go; this is embarrassing enough without having to tell my parents. Maybe...maybe I can get past this? But maybe not. I don't want to decide right now."

I nodded, again. "I get that."

Then her lips formed into a thin line. "Right now all I can think about is how I could fucking kill Summer, though. I can't believe she did this to me. I'm her sister. She's always been jealous of what I have, but

this

..." she trailed off, obviously stewing. "I need to think about what to do. Don't tell anyone or give her indication I know, okay? I want to decide how to confront her."

I agreed. I was silently grateful that Summer seemed to be the target of most of her ire.

Eventually, mostly in silence, we headed back towards the cabin.

The rest of the day was obviously tense. Summer was pissed at me. Jessica was pissed at me. Jessica was pissed at Summer. But they were both doing their best to hide it from each other.

Later that afternoon, Jessica and I finally had another minute alone in our room to talk. Summer and her parents were out by the pool.

Jessica turned to me. The expression on her face was neutral -- scarily so, I thought -- but I could sense the rage simmering just under the surface. "I've thought about it, Jason, and I'm so pissed at her, walking around pretending like nothing has happened. I'm going to get some fucking

revenge

. And you're going to help me."

It wasn't a question.

This felt bad, across the board. But it's not like I could say no, and I knew hesitating in this moment would be fatal. I nodded. "Of course. I'm on your team. What's the plan?"

Her lips curved up into a smile that was almost cruel. "I want you to fuck her. One last time. I want you to get her off, make her cum hard. While you're doing it, I want you to ask her a few questions. Get her to say a few things. I don't want to record her or anything like that, but I want to hear it. And then I want her to

know

I heard it."

Uh oh. My heart sank. "W-what kind of things?"

She outlined the questions she wanted me to ask, the prompts she wanted me to give Summer, what she wanted to hear her sister admit and say. They weren't, in the end, so bad, given what Summer and I had done. Not especially humiliating or anything, I thought.

"...Okay. I can do that."

She pursed her lips. "We'll do it tonight. I'll make an opportunity for you."

I nodded.

"And babe?" Jessica's voice was quiet, now.

"Yeah?"

"

Do not cum

when you fuck her. I want you to get her off, to make her say all the things we talked about, but you only cum for

me

, now."

The threat in her voice -- the anger, underneath the surface -- couldn't be clearer.

I nodded, hastily. "O-of course..."

Uh oh.

---

I was terrified, now.

Being dominant enough to get Summer to say the things Jessica wanted to hear was possible, I thought. Summer had certainly seemed to enjoy our most recent encounter, obviously liked talking dirty while I fucked her.

Making Summer orgasm was another thing entirely.

And doing all that without cumming myself...

Well, I didn't like my odds.

Especially since I had gotten right to the edge, but

hadn't

orgasmed this morning. I tried to find a quiet moment to jerk off, thinking it would improve my stamina.

It was impossible, of course -- the walls were thin, someone was constantly about as people came and went. Jessica ran some errands, but Summer was still in her room. Then Summer went out by the pool....and Jessica's mom asked for help prepping dinner. And then Jessica was back...and it's not like I could ask Jessica to help me. What was I going to say?

Uh, hey, it'd really help me last longer with your sister who I've been cheating with if you helped me empty the chamber beforehand?

So I resigned myself to just doing my best. It wasn't like I had a choice.

We had dinner outside on the deck again. Another nice evening. Her parents headed to bed shortly after sunset. It was just Summer, Jessica and I. The first time it had just been the three of us since I had told Jessica I was cheating on her with Summer.

There was a palpable tension in the air, although I'm not sure it landed quite the same way for Summer and Jessica as it did for me.

As a result, we chattered on for a while, before Jessica, glancing at me meaningfully, said, "So...Summer, got your eye on any guys back at school for when it starts back up in the fall? Any that are boyfriend material?"

Summer was wearing workout attire; she had gone for a walk before dinner. Emerald green leggings and a matching crop top. To be honest -- with how pissed off I knew Jessica was -- it was easier to keep my eyes off of her than it had been. But I still found my gaze following the way the crop top pushed up those big tits, the shelf of cleavage it created, the way her tits had looked this morning, naked, bouncing while I fucked her...

"Oh, a few, I guess," Summer said, a little dismissively. "There's one or two guys in particular who I see at the campus gym every now and then who might be fun; they like it when I wear this outfit, actually. But I don't know...boys just seem to

disappoint

me, you know, Jessica?"

As she spoke, Summer stood up, and took her drink to look out over the railing of the deck into the barely-visible outlines of dark trees. I was staring at her silhouette, now, her ass especially -- appealingly round, filling out those leggings.

Jessica continued. "Oh yeah? I guess I used to feel that way too, until I met Jason...he gives me everything I need...maybe you just haven't found the right guy yet..."

"Mmm," Summer mused. "How'd you know Jason was the right guy?"

Jessica looked over at me, a complicated expression on her face. "Oh, he proves it to me every day. The way he acts, you know?"

"It wasn't the chemistry in the bedroom?" I could hear the smirk in her voice.

"Oh, that too." Jessica was still looking at me, her mouth twisted into a sour smile, now. "He always surprises me."

Summer paused, still staring out at the night over the woods. "You okay, Jess? You sound...a bit off."

Make her cum. But YOU don't get to.

Jessica mouthed the words at me, barely visible in the dark, and then said, "y'know, my stomach feels a little weird...maybe the same bug that you had the other night, Jason. I think I'm gonna turn in. Don't worry about me, finish your drink, babe, I'll see you in a bit."

She turned away and headed inside, the screen door -- but not the glass one, I noted -- shutting behind her.

"Hmm," Summer said, quietly. "She seems out of sorts." She was still looking out at the darkness, facing away, but I could hear the suspicion in her voice.

My heart was pounding. "Just sick, I guess," I ventured. I had to make a move now, I realized. Summer was sharp. I didn't want her to think about it too much. I needed to distract her.

I stood up, coming up behind her as she stood leaning on the railing of the deck. I moved close enough that I was brushing up against her ass -- she was soft, and felt warm against me through our clothes. I leaned over her. "I've been thinking about this morning," I murmured in her ear.

I heard her sharp intake of breath.

"Oh? What have you been thinking?" she asked the question coyly, and pushed her ass back into me. I was getting hard in spite myself, in spite of all the tension, the guilt, the performance anxiety. Fuck, her ass felt good, nestling up against my cock.

But I tried to stay focused. Dominant. I wanted her responding to me, answering my questions, not the other way around. I wanted to be leading this interaction, couldn't afford to let her take charge. I wrapped both hands around her waist, feeling the warm skin between her leggings and her crop top under my fingers. She let out a little sigh.

"I've been thinking how hot it was to hear you telling me to use you," I whispered in her ear.

"That's funny, because you

stopped

after I said that...almost like you couldn't handle it..." she murmured the words out, still sounding annoyed. She was grinding back rhythmically into my cock, now.

I winced. I thought Jessica had headed inside for a little, would probably wait until Summer was truly distracted to reappear, but I didn't want her to overhear Summer teasing me about how fast I came for her. "Maybe we'll see what

you

can handle," I muttered.

I reached down and grabbed the waistband of her leggings, stripping them down to her ankles in one sudden movement. She gasped, but it was a pleased gasp.

I slid one hand down around her ass and between her thighs. God, she was wet already. Really wet. As I traced my fingers over her, I asked her a question she had asked me only yesterday. "You didn't get the chance to finish today, did you?"

"N-no..." she stammered, as my fingers roamed between her thighs. I took a half-step back and unzipped my shorts, dropping them and my boxers to the ground.

As I did that, I glanced over my shoulder. Inside the screen door, barely visible in the night, I thought I saw Jessica's shadowed silhouette.

This felt wrong -- but knowing Jessica was there firmed up my resolve. She

wanted

me to do this. Wanted the chance to teach Summer a lesson.

Summer pushed her ass back against my cock. "Fuck me," she said, urgently, "please."

That was hot, but Jessica's presence jolted me back to the fact that I was supposed to be getting Summer to say a few things.

"You love getting fucked by your sister's boyfriend, huh?" As I asked the question, I lined up my cock -- rock hard in spite of the mix of guilt and anxiety I was feeling -- between Summer's thighs. The swell of her soft ass against my hips felt incredible. I teased the thick head up and down her opening.

"

Yesss

," she hissed the word. "God, it's so hot that you can't keep from fucking your girlfriend's slutty little--

ungh

, god..."

As she was talking, I realized there was some real risk Summer would say some things that would just piss Jessica off further, or reveal that Summer had been getting me off easily, not the other way around. I was playing with fire.

So halfway through her sentence I cut her off by hastily starting to slide my thick length inside her. It worked, stopped her talking, but

fuck

. She felt incredible around me. I hoped she was more turned on than I was, because I wasn't going to last long.

I tried again. "You've had a crush on me, haven't you? Ever since you found out your sister's boyfriend was packing a thick cock, heard how well I take care of Jessica in bed, you just had to have it..." As I spoke, I reached down and took a fistful of her hair, grabbing close to her scalp by the base of her neck.

"God, that big dick feels so good," Summer whimpered in response. I could feel her get wetter as I forced her to arch her back. She pushed herself back onto my cock as I thrust into her, her plush ass bouncing appealingly with each thrust. And with each bounce, I could feel the orgasm growing closer, more urgent.

I tried to refocus. I couldn't get caught up in how good Summer felt. This was a performance for Jessica.

I grabbed her ass with both hands now, started fucking her harder, leaning over her. I tried not to think about how good her ass felt in my hands, the way she felt around me, tight, wet. The way she moved.

Jessica didn't fuck like this

. I couldn't help the thought.

But I stayed focused. I tried again. "Yeah, you love that cock," I said, right in her ear. "You've always been jealous of Jessica, haven't you? Model looks, good grades, hot boyfriend. She's got her life together and you're just her little sister..."

"Oh, f-

fuck

," Summer gasped. The overwhelmed sound she made as I picked up speed was incredibly hot. "Okay, y-

yeah

, I've always hated how much everyone loves her, she's always been such a good girl...but here you are, railing me instead of her, fucking me with that big cock, cumming

so

fucking fas--"

My face reddened. I didn't want Jessica to hear that. I slapped Summer's ass, cutting her off again. She let out a little

ah

, then looked back at me, mouth open.

"Mmm...I didn't know you could fuck like this...I-I'm gonna cum soon, Jason," she moaned. " I was so close earlier..." She sounded absolutely out of control, and -- looking down at the way she was frantically bouncing her ass back into me, moving with wanton abandon -- I knew it was only a matter of time before I lost control completely as well.

It was incredibly hot. But I hadn't done enough yet. I glanced back over my shoulder at the screen door. Jessica was just barely visible, watching intently. I couldn't see her expression in the shadows.

"You're so jealous of your big sister, aren't you, Summer? Admit it. You wish you were getting railed by my big cock all the time, like she was, that's why..." I trailed off, wrestling with the mounting sensation of my orgasm.

Shit

. I had to slow down, I realized. At least for a little. If I didn't, I was going to cum.

"Y-yeah, I am jealous, she gets your big dick all the time, that's..." she looked back at me, curiously, realizing I had slowed, and she got a sly smile on her face. "C'mon, you're not gonna cum for Jessica's little sister, are y--"

I spanked her again, and it cut her off again. But my heart wasn't in it; I was too busy focused on keeping myself from tipping over the edge. She let out a wanton sigh, and started pushing her ass back onto my cock. "Mmm, yeah, let me work that big dick..."

I was in trouble, now, I realized, feeling overwhelmed as she began rolling her hips to a quick, steady cadence, that plush ass pressing against me, bouncing off of my pelvis.

If she didn't cum soon, I was absolutely going to blow my load. I only had a little more time. Leaning over her, I whispered in her ear, "I want you to cum for me. Cum all over your sister's boyfriend's cock."

She started moving harder, more forcefully. "Okay...b-but I want

you

to cum with me-"

And then I reached around and found her clit, delicately tracing it with one finger, my other hand gripping her ass hard.

She froze as I touched her, almost quavering, like a bowstring stretched as far as it could go.

And then, with a low cry in the back of her throat and a tremor in her legs, she started trembling, almost collapsing against the deck railing. She was still pushing back against my cock, and I thrust into her a few more times.

I'd like to say I enjoyed it. I had been thinking about making her cum for days, after all. But the reality was, I was preoccupied.

I had gotten so close earlier, and these sensations were almost overwhelming. Summer's soft ass, bouncing into my hips. Her body shaking, the moans as she came, were so hot.

Every fiber of my being had to fight the urge to just cum with her, to just fuck her through her orgasm until I came, too. It would be so easy, feel so good. And in a few seconds it'd be inevitable.

I knew Jessica was watching, though. I knew that blowing my load would be the ultimate betrayal of her. I didn't want to do that...

And that meant there wasn't any way I could keep fucking Summer.

As a result, after only a few more thrusts, I pulled away. I had to. She let out a desperate, frustrated whimper as I pulled my thick length out of her.

"Jason, I was still going, what the f--" she turned around.

I couldn't respond, was struggling with whether I was going to keep control, or if I was just going to spill my load on the deck even though I had stopped.

But it turned out, I didn't need to respond.

"No, what the fuck

yourself

, Summer." It was Jessica, voice flat and furious, stepping out of the shadows.

Summer, flushed from her orgasm, panicked and disoriented, looked back and forth between me and Jessica. "I--

he

--"