Fuck yes! As if you could refuse.

"I've already got contraceptives taken care of, if that eases your fears a little." It hadn't struck you immediately, but Theresa's reassurance does keep additional concerns from bubbling up. The last thing you want to imagine is impregnating your sister in your first intimate experience.

...Oh shit, you're really about to do this, aren't you? You can't fathom backing down, not underneath that perfect, toned ass pushing on your cock.

"Can... c-can we go slow, sis?" Your voice is breathy and weak, lungs too focused on keeping you conscious, pumping oxygen into your muscles priming for use.

Her eyes glimmer with excitement, a wild grin curling her pretty lips. "Of course, Bubby! The first time can be scary, and I just want to show you the ropes. And, y'know, make you feel so good you worship me." Tongue stuck out, giggling like a child, you just don't understand. How is she so chill about this? It's... well, it's soothing, really. Even like this, Theresa is still Theresa. She didn't suddenly become a different person just because she's horny and suddenly becoming topless oh my fucking GOD, TITS.

In another swift, practiced motion, that well-filled bra comes up and away, making a soft flump on the floor nearby, your sister's chest bared for your personal viewing pleasure. They're perky and beautiful, capped with firm little eraser cap nipples. Her own hands run up and down the soft flesh before moving out, taking you by the wrists and guiding your hands toward them. "Nothing slower than a little grope of the boobies, hm?" Her giggle melts into a pleased cooing sigh at your touch, eyes closing and giving you the freedom to explore.

Your hungry, inexperienced hands squeeze and rub, rolling your fingers across the supple flesh of Theresa's firm yet pliant breasts. Your thumbs graze over her stiff peaks, causing a happy gasp to escape. Porn can at least get you this far as you give those tasty pink nubs a pinch. Theresa hisses and coos, glancing down at you with one eye.

"Go easy, Bubby. We just started. You can be a little rougher when we're really getting into it."

"S-Sorry..."

She shakes her head. "Don't be sorry. You're learning." While you grope, Theresa's hips start to roll and grind again, sending wonderful electric ripples of rhythmic delight through your nerves. "The most important thing to know is, mmnn... is to listen to your partner. Their words and their body... everyone's different, so make an effort to..." Laying her hands over yours, she gets you to really mash her tits with your fingers instead of lingering on her nipples. "...learn from them."

You can feel moisture starting to build in the front of your pants, both from inside and from out. Your eyes track down, admiring Theresa's toned, defined stomach all the way to that small damp spot between her legs. A pulse of desire from the realization that your sister isn't just wet, but dripping in arousal, ripples from you and into her, making her shudder and clench her thighs against your hips.

"Mnngh... alright, I get it... Bubby wants more than my big titties." She giggles softly, fingers working on the buttons of your shirt. "But I'm not the only one getting naked. You've gotta show me your goods, too..."

As if you could say no. As your sister climbs off you for the moment, you half scramble to undress, ejecting your clothes as if they're magnetically opposed to your body. When it comes to your underwear, though, you hesitate. Theresa, meanwhile, is eyeing you like a primo steak, hungrily nibbling her lip. She's been watching? Of course she has, but at least she looks eager and not just amused.

"Well? Show me what I'm working with!" She flutters her lashes at you, pressing her breasts into a lovely, bulging valley of cleavage, puckering her lips for you.

"I... I just... I'm not huge, okay?" Might as well get it out. "Don't... don't laugh."

At that, she pouts, getting briefly serious. "Gavin. It's not about size, no matter what people say. I wouldn't laugh even if you hadn't ordered me. Unless it was in surprise that you've got a monster down there!" She winks at you, ever playful.

Holding your breath, you clench your eyes shut and yank downwards, stepping out of your underwear as it hits the floor. You dare not move until you get a reaction from your sister...

"Ohh... Bubby." What? What was that supposed to mean?? It's small, isn't it?? You knew it, this was a terrible—

OH. Oh, that's a hand-- HANDS, on your junk. Your eyes snap open, seeing Theresa knelt down in front of you, hands exploring your rigid shaft and cupping your balls. She grins up at you, mischievous and hungry.

"I guess you were right. You're not huge, but... this is a good size," She doesn't break eye contact with you, lips lovingly parted as she starts to stroke you. "Very, very nice. It's pretty thick, too... that's more important than length, in my opinion. Something that'll really fill me up..."

"...Really?"

She nods, grinning. "Really. I've had huge ones before and let me tell you, having your cervix pounded into putty is not as delightful as porn makes it seem. Totally honest, Bubby, but you look to be a pretty perfect size. I won't know for sure until I take it for a test ride."

This... isn't at all how you expected your first encounter with a girl would go. It's still awkward, sure, but any fears or concerns you have are immediately washed away by Theresa's gentle words and dear fucking GOD those smooth hands of hers.

When you feel her tongue lap at the underside of your cockhead, though, your body goes rigid. Your cock throbs in warning, teetering on the edge already. Theresa picks up on this quickly, urging you to sit down on the bed.

"Oooo, lesson number two: Rubbing out the easy one..." Those hypnotic hazel eyes glitter with excitement, your sister licking her lips and nestling herself between your knees. "Don't be nervous Bubby, just let it go. The first one's always quick, especially after a dry streak."

Before you can ask, her hand starts pumping your shaft, tongue firmly pressed against the tip. Her mouth sits wide open before you, eyes pleading for your load. "Cum for me, Bubby," she gasps. "Make a big mess for your sister..!"

It's too much. Your fingers grip the bed sheets, every inch of you clenching and flexing as you feel your loins explode. One hard throb after another, you give Theresa what she asked for. Thick coils of white spray into her mouth, making her coo and moan for you, though one particularly ambitious streak jumps up across her face, forcing her to close one eye. Once those blissful, mind-numbing eternity of seconds pass, you let out a growling sigh, breaths coming hard and heavy.

Theresa gives a throaty giggle, swallowing the whole mess right in front of you. "Oooo, and you don't taste bad either." She wipes the errant cream off her face, taking it all away with her tongue in a heart-gripping display.

"Sooo, what'cha think?" Her tone is upbeat and bubbly again, pushing you back onto the bed proper so she can sidle up beside you. Her panties don't make it onto the bed with her. "It's a million times better than using your own hand, right?"

You blindly nod, still trying to come down out of the stratosphere. Whatever you just mumbled sounds affirmative, so Theresa takes it as praise.

"And that was just my hand! And a little tongue, okay, but it gets so much better." Oh, joy. This seems like a nice way to die, so why not? "So, while you recharge, why don't you try reciprocating?"

"Huh?"

"Big Sis wants to cum too, you big dork." She grins playfully at you, still giving your currently softening dick a few gentle rubs. "I used my hands, so you use yours!"

Sitting up, you glance down between Theresa's legs. Her pussy is very neat and tidy-looking, masterfully groomed with just a tiny tuft of fuzz right above her slit. Shimmers of moisture glint in the low light, further emphasizing her arousal to you. Sweat and flowers and...

"How do I... y'know..." Hands willing, but head big dumb. Help.

"Here." Hip to hip with you, Theresa takes your closer hand and places it over her sex. The heat is daunting, but when your fingers meet the damp skin, both of you get a jolting tingle in your spines. "Just go slow. Explore. I'll help."

So you do. At first, your fingers warily glide over the moist surface of her slit, feeling the soft flesh of her lips part with just a little pressure. Theresa rests her head on your shoulder, rewarding you with breathy coos and content sighs whenever you hit a good spot. When you graze her clit, she tenses and gasps softly, but quickly urges you to continue. Your growing lust and her growing pleasure make her breathing ragged, the hot puffs of air on your neck making you stir again.

Finally, you slip a finger in, making Theresa's back arch as she grips onto you. "Good. Good... now just, curl your fingers a little... back and forth... yes, just like that, yes, keep going..." Her lips tap against your earlobe as she moans, making the hairs on your neck bristle. She whispers, "Keep going, Bubby..."

One finger becomes two, Theresa's encouragement urging you to go faster. The messy shluck-shluck noise of your fingers starting to piston into your sister's cunt is shamelessly lewd, but you love it. You love the feeling of her melting into your grip, practically humping your hand as you bring her pleasure. These sounds she makes from your actions, the sight of her wriggling in delight against you... it's positively intoxicating.

When the time is right, Theresa murmurs for you to focus on her little love button. She desperately moves your fingers over her clit, trying to help you rub it just right as her pleasure builds. She moves her own fingers into her snatch, pleading for you to buzz the fuck out of her most delicate point. You greedily comply, eager to see the culmination of this "lesson" unfurl before you.

A whine of tense release soon grows into a primal wail of pleasure, Theresa's thighs and loins flexing and spasming as an orgasm rocks her body. She twitches and thrusts against your hand, moaning loudly in your ear as her free hand holds onto you for dear life. Her nails dig in a little hard, but the minor sting only exacerbates the incredible satisfaction you devour in bringing your sister to such an intense climax. Her hand and yours both become soaked with her juices, leaving the air heady and sour-sweet with Theresa's aroma.

Wildly curious, you bring your fingers up to your face. Locking eyes with Theresa, you bring them into your mouth, taking in this small sample of the flavor you may well experience directly in the near future. It's... a foreign flavor, but not at all unwelcome on your tongue. You clean your fingers, Theresa watching with heaving breaths and wide, needy eyes.

Her eyes flick down to your cock, rising back to the occasion, then back to yours. "Fuck me. Now."

In a sudden burst of calm and cockiness, you grin at your sister. "Who gives the orders around here, Tess?"

Her mouth drops at your words, but quickly turns into a wild, ecstatic grin. "Please, Bubby. Fuck me. Fuck me good. I've been a good girl, right?"