Spending Friday Night with Theresa.

That night, after dinner, you've not had any success in searching for your signature around the house. Given you don't need permission (it's your house now), you even did a little snooping around in what used to be your bedroom, now your parents'. Nothing odd or signed to speak of. Damn. You could swear it would have been in there, since it would be the easiest place to hide something from you.

Then again, sis told you that it wasn't hidden. Something you see every day. How does that make sense???

Defeated once more, you have a feeling you're just going to have to wheedle it out of your sister when she gets home tomorrow. It's not as much fun, but you know when you're beat.

It's not quite time for bed yet and you have one last tactic you can think of: ask for help. Mom and Dad are still in the living room, letting the TV play as background noise while they wind down. Mom notices you enter the room first, smiling warmly at your approach.

"Hey, sweetie. Was dinner okay?"

"Wonderful as always, Mom." You give her a small peck on the cheek, making her sigh happily as your eyes still go over the room.

"Something on your mind, baby?"

"Yeah..." Tess might count this as cheating, but that would imply there are rules to begin with. "Mom, Dad, have you seen anything around here with my name on it?"

Your parents bristle for a second, glancing around the room.

"Y'mean besides the house itself, son?" Dad sounds put off by the question, not looking up from his tablet. Jeez, is he still grumpy about your house rules? The lack of cigars might be hard on his system, you figure. You brush it off, more distracted by your potential quarry.

"Yeah, something in the house. I've been looking for a whole week and I can't find anything."

"Haven't seen a thing," says Dad, pointedly not looking your way. Mom's whole face is glowing pink, her eyes repeatedly flicking over to her husband. They know something. They know, but they're not saying? Mom was always terrible at keeping secrets; no poker face at all. If they're intentionally keeping it from you, then that means Theresa has already recruited them in her game and told them to play dumb. Man, once again she's a step ahead of you! Still, knowing it's something your parents are aware of helps a little bit... but not much.

Something claimed... something you see every day... that isn't hidden. What in the world could it be? Respecting the side they've chosen, you let the matter drop for now and instead just spend some calm hang-out time with them in the living room before bedtime. You'll get the truth from your sister soon enough.

Friday's classes come and go, as usual. The class work is simple, and you have no doubts you can finish your dwindling flow of homework in no time. It's senior year: once your major projects are wrapped up, it'll be smooth sailing until graduation, leaving you plenty of time to focus on other plans. You pass Penny in the halls, managing eye contact and a wave without glowing like a light bulb, which she returns in kind. You hope she's looking forward to the aquarium half as much as you are. She hasn't texted you or anything yet, but there's still plenty of time.

You haven't seen Izzy today, either, making the start of your weekend even better. No mention of her folio status. Before that can change, you're more than ready to leave the school behind and get home the moment the bell rings. You've been buzzing with excitement, eager to see your sister again and continue to work out your powers. She's going to tell you what her present is, even if you have to order her today, but you're still going to try to wring it out of her one last time first.

You're naturally home before her, as expected, but if you know her schedule, she shouldn't be more than an hour or so from arriving. That gives you time to chuck your backpack into your room and hop in for a shower. The jog home has you a smidge funky, and for some reason you want to be crisp, refreshed, and presentable when she sees you again. Mom barely gets a greeting out before you give her a drive-by peck on the cheek and zip up the stairs, leaving her spinning.

"That boy sure does have a lot of energy these days," she muses with a soft giggle.

~

Whatever you were doing when you hear the front door open doesn't matter as you fly down the stairs, catching a glimpse of Theresa setting down her overnight bag on the couch. Matching your energy, her face lights up when you approach, her arms opening to catch you in a big hug. She laughs like music, burying her face against your neck for a moment before bringing you out to arm's length.

"Mmm, good to see you too, Bubby," she quips, nibbling the corner of her bottom lip. "If that's the kind of greeting I'm getting now, I'm going to have to come home more often."

You smile bashfully, stepping back to give her space. Your front immediately feels cold with her absence. "Sorry, but aren't you excited? So much has happened!"

"Oh, I know!" She's bouncing right along with you, stepping into the room proper. "We talked over the phone, but I wanna hear it from you directly! Tell me every little thing, every detail! Was Penny as wonderful up close as you hoped?"

"Oh, a thousand times prettier, and just as smart."

She bats your arm. "As if you'd say anything else."

Mom soon catches you two in the living room, also pleased to see her daughter home. You get a wonderful side view of their chests bulging together in a loving, normal, familial hug, stop it you.

Theresa glances your way, grinning like a cat at your red cheeks. Uh-oh. Did she notice? If she did, she's not saying anything... which might be worse.

Dinner was normal for a Friday night. Theresa recounts her week's activities to your parents, laughing and talking jovially with them while you remain mostly quiet. It's still better than it used to be. Your silence used to mean you were trying not to exist, since catching anyone's attention just meant more teasing from Theresa. Now, you're just happy to listen, feeling like you're actually part of the warmth your family exudes together. Theresa even brags that it was her pushing that scored you a date with Penny, which you can't entirely argue against. Dad's just happy to see you taking initiative and is confident you'll do fine.

Mom, though... she's distracted. You only really notice it when you all actually sit together for dinner, but she's glancing over at her husband pretty often. Whenever their eyes meet, her stare turns into a smolder, a hand reaching somewhere under the table near his leg. Bedroom eyes. A complex expression rolls over your father's face, but ultimately ends in a grin. Once dinner is finished and the dishes are put away, the four of you pair off and excuse yourselves for the evening.

While your sister follows you upstairs to hang out in your room, you can't shake the redness in your face. Mom is horny, and she's going to probably ride Dad again tonight. They're going to fuck on your old bed, in your old room. Mom's going to make a lucky bastard out of Dad all over again. Muscle memory guides you into your bedroom as your thoughts and vision are clouded by memories of that sumptuous hourglass bouncing up and down, up and down...

"It's kinda hot, isn't it?" Theresa's question startles you, forcing your gaze onto her. She's only wearing a loose tank top now, so bits of her colorful sports bra through the holes. Her shorts ride hide on her toned thighs, accentuating her long legs nicely. Short little socks hide her dainty feet and toes, which you find weirdly cute and sexy at the same time.

"I mean, it's sweet, but in a hot way," she continues. "Their flame hasn't dwindled after kids, after all these years. They're still in love and ready to show it in the best way."

"Yeah, I... I guess that's one way to look at it. I'm glad they're happy, if anything."

Theresa clicks her tongue at you, noting your wholesome dodge of the subject. "Mom looks good for her age, too, don't you think? She's taken pretty good care of herself. Dad too, if he'd work off that gut he has. They might get even more fierce in bed once the exercise gets him back in shape."

Your face glows as you flop down onto your bed. "How are you so calm talking about our parents and... and sex, in the same breath?"

She just shrugs. "I dunno. It's just sex. Sex is what people do, it's not a big deal."

"Maybe not for you, sis..." You let an arm drape over your eyes, darkening the world around you. You feel the bed shift, Theresa finding a spot beside you.

"I think I already know the answer, and don't think I'm teasing you for this, Bubby, but..." there's so much mischief in that tone, how can you not feel teased? "...Are you still a virgin?"

You groan loudly, rolling away from your sister. "Yes, I am, thank you for reminding me."

"It's okay, Bubby, really! It's nothing to be upset about, we all have to start somewhere. I was still a virgin getting out of high school, too."

Your eyes snap open and you wheel around, balking at her confession. "No way! You had, like, a million boyfriends!"

She blushes and giggles softly, twiddling her thumbs. "Well yeah, but I didn't go that far with them. They were still just boys, and I didn't want to. I might be popular, but I'm not some shameless slut who'll go for just anyone. No, I didn't find a guy who was worth it until college. And another, and... well, that part's probably closer to what you imagine."

You groan again, trying not to think of your sister with another guy. Wait... another guy? She's got you thinking weird shit again.

"A-ny-way," she pushes, overenunciating each syllable, "What I'm trying to get at is... well...are you worried about it?"

"About what?"

"About being a virgin."

That's... kind of an odd question. "Are you asking if it bothers me?"

Her head bobs around, somewhere between a nod and a shake. "Yes and no? I guess, more specific, are you worried about being a virgin... regarding Penny?"

Oh. OH. Realization washes over your face, and you're quickly red as a beet. "Wh-wha, I just, I— we're just going to the aquarium!! God!!"

Theresa's hands go up, a calming gesture. "I know, I know! Chill, dude, geez! You want more than that eventually though, don't you? You like her, right? You want to be with her someday? Don't you think, if it goes well, that things will lead toward sex?"

"Of course I do," you blurt out. "She's fucking gorgeous! I'd give anything for a night with her in bed. I would..." Your heat fades quickly, words falling flat as you realize...

"But you have no idea what to do, right? Porn's not going to teach you how it really works."

Falling back against the bed, you stare at the ceiling. "And what of it? That's how being a virgin works."

Finally, Theresa brings the knife out in the conversation. "Well, I was thinking... I could teach you a few things."

...

What? What? WHAT?

You dare not move, only tracking your sister with your eyes. Her face is pretty red, eyes scanning over your body up and down.

"I know you've been thinking about me," she murmurs, her voice soft and sultry. Inviting. "I can feel it."

Propped up on your elbows, horror and curiosity swirl on your face. "What do you mean, feel it?"

Hooking a finger by her ankle, she slowly peels one of those cute little socks off her feet, wiggling her freed toes. "Remember when we were in the car? When you compliment me, I feel warm and fuzzy. When you insult or berate me, I feel a stinging pain. But, at the mall, at the gym... and right now..."

Before you can protest, your sister swings her leg out, straddling your waist with her hands on either side of your head. Your breathing quickens, looking up at those twinkling hazel eyes, a curtain of wavy brown hair masking her pink cheeks from being seen by anyone but you. She feels so hot against you, the point of contact between you two positively burning. Unable to look away, you can make out two firm points poking through the fabric of her mostly exposed bra.

She smells like sweat and flowers.

"Bubby..." she leans in closer, only needing to whisper, eyelids fluttering. "When you think of me... like that... I feel it, too. You own me, Bubby. I can feel what you want from me." Grinding against you, Theresa's hips roll lower, her heated crotch bumping into the tent trying to bust out of your pants. You just lay there, paralyzed by the surging, roiling sensations churning in your body. Fear, excitement, lust, anticipation... you can scarcely breathe.

"If you want to impress Penny... you need experience. I can help with that." She's already peeling her useless tank top away before you can answer.

"B-But... we're siblings... you're my sister!"

She giggles, sitting upright atop you, tapping your name on her arm. "Yes, I am. But beyond that, I am your property. Sister or not, you can do what you want with what belongs to you."

You groan and shudder, making Theresa giggle as your cock eagerly throbs under her round ass.

"I can teach you all sorts of things, Bubby. You don't have to think of it as sex if you don't want to. Think of them as lessons. I'm helping you prepare for Penny. I want you to be able to blow her mind as soon as the moment arises. How many virgins do you think get this kind of opportunity?"

Damnit... Damnit! How can she be so logical, so persuasive and cool-headed while mashing that burning mound against you? You want her and she knows it. She can feel your lust for her, which only makes her hotter for you. She wants it, too. You can't think of a single good reason not to submit, and a thousand signals roaring in your mind and in your dick to go along with this.

But it's Theresa! Tess, your big sister! Can you really go through with such a forbidden, dangerous act?