Offline/She's happy, put your pencil down
Your sister's happy and that's a way better outcome than you could have hoped for. But this is as fortunate as it is weird and you don't want to come off as even weirder by making her lay back down.
Closing your pad, you start to put it away when Em excitedly hops up onto her feet.
"Wait! Don't stop! Let's do another one!"
Em didn't shock you enough the first time it seems. Standing right in front of you, your sister strips off her shirt, tossing it away, and poses Superman style with a big smile, her hands on her hips.
"Em... what are you doing?"
"Duh. Helping you practice!"
That's a dubious claim at best. There's no way that's the only thing motivating her and you both know it. She's probably going to gab with Asha about this later, or use it to make fun of you when it suits her. But... if she's just gonna stand there naked...
It's a very unnatural pose, and one that neither of you are entirely comfortable with; You can see Emma's cheeks are flush, and your ears feel like they're burning. You want to make this a very fast sketch but it still takes you a couple minutes to get something you're happy with, pride and ego slowing you down. Em rambles the whole time about how her friend said she could be a model and asking if she should turn this way or stick out her butt. You just tell her to hold still, shamefully wanting to capture the all but nonexistent curves of your little sister's perfect pencil figure.
Despite your desire for accuracy, when you finally get to her crotch (which you leave for last) you can't bring yourself to detail her pussy. It just seems wrong, like you'd be taking advantage of your innocent sister posing like this. So, to placate your guilt, you just connect the inseams of her thighs together with a straight line. Of course when you hand over the drawing that's the first thing she notices.
"What's wrong with my privates?"
"What? Nothing."
"But I look like a Barbie. How come you didn't draw my lady bits?" she says with an immature giggle.
"I... I can't draw that, sis."
"Yeah! Exactly! And since you don't know how then you have to practice!" Emma steps closer, standing right in front of you, her crotch two feet from your face. "Can you not see it? Is this better," she taunts, wiggling her hips and wearing a big grin.
"Em, quit it. I drew you, okay? We should get b-"
"Draw my privates!"
"Emma. I don-"
"What's wrong! They're just girl parts. See?"
Rising to her tippy toes and pushing out her hips, Emma cranes her head forward while her knees go outward to help her peer down at herself while she pries her vulva apart directly at your eye level.
"Emma!" you exclaim, wincing, but you sure don't look away from the supple strip of pink revealed and framed by your sibling's dainty fingers, showing off her nubby clit and dainty labia contained within her slit.
Your sister openly giggles at herself. She was having fun before but she has to be fucking with you now. You don't want to overreact, but she's also expecting you to react rather than just stare.
"What the hell, sis?! You wanna pose like that too?"
Calling her out gets her to drop back onto her heels. Em chuckles some more after shielding her crotch for once with her hands. She's "just kidding" apparently, and is quick to put panties on, actually looking embarrassed for once. She has to know she shouldn't be doing shit like that but she's tickled with herself either way. Guaranteed she tells Asha all about it.
With Em shamed into being sensible, you both decide to get changed. But instead of hiding in your sleeping bag you also do it in the open, trying to demonstrate your comparative maturity. But you also struggle to not flash your semi because Em starts moving around the room as soon as you've stripped and you quickly put on some boxers trying not to fall over.
This was all super weird, but it's over now. You just want to get back to camp so you can get away from your idiot little sister. Of course she only seems to know how to make things more awkward.
"Sorry about touching your penis last night."
God dammit.
You freeze, glancing over at her. It sounds like a sincere apology. But why does she feel the need to talk about everything? It's weird enough hearing her admit that she knows she tapped your dick at all, as if there was any doubt.
"Um... yeah... that's o-"
"Does it have to get like that for you to sleep?"
The fuck is this?! You throw a double-take at Em like she just kicked a dog. Why can't she be normal?!
"Whuh? Em... I don't even know what you're talking about. Just stop," you warn, trying to feign ignorance and shut her down all at once.
"I mean how it was all hard."
Nope! Nope-nope-nope. You are not about to admit to your sister that you had a boner while she was bunking with you, let alone that she touched it. But you can't bring yourself to address it either. You just glare at her and shake your head like she's so incredibly dumb and has no idea what she's talking about. Buuuut she does...
"It's just that your thing was hard this morning too when I woke up, and so I thought maybe it has to get hard for boys to fall asle-"
"Stop!" you blurt out, stepping towards the door. "Stop talking! Oh my god!"
"I was only curious," she shares, walking after you still pulling down a frilly sleeveless top as you usher her out of the cabin. "Because I thought it was weird, but maybe they just work like that. Like, it gets hard when you lay down, or so you can sleep, or-"
"That's not why guys get hard," you interject sharply, unintentionally insinuating the truth.
"Oh." Emma walks beside you for a moment before connecting some dots in your head, connections she must not have thought were possible until this moment. "OH!" she exclaims. Granted, you didn't know you felt that way either.
"No!" You're quick to interrupt her thoughts again, this time stopping on the trail. "It's not that either! That's not why I got hard! Guys get hard-ons for all sorts of fucking reasons, okay? And yeah, sometimes it's because of girls, but sometimes it's for no reason at all. So can you just drop it?"
You start walking, Em sticking close to you, but for once you're the one who can't shut up. You only make it a few yards before putting your foot down and pointing your finger at your sibling.
"...And another thing! Why were you looking at my dick this morning anyway? What's wrong with you? I told you to sleep by yourself! I just sleep naked okay?! Guys get erections all the time... and a lot more fucking often when I can't even deal with it! So leave me alone! Jesus! I was hard! So what?!"
Only after you finish your rant do you notice Em has a smirk on her face. It's growing too. As her smirk widens, your glare strengthens. But eventually she just can't help herself, breaking out into song.
"Your sister gave you a bowww-ner! Your sister gave you a bowww-ner!"
Emma gleefully skips around you in a circle, taunting you with a schoolyard chant that you'd hoped would be beneath her by now. But she finds it too funny to pass up.
You give her a moment, looking up at the sky and shaking your head while letting her dance away some of her giddiness. You don't even know why she thinks this is so funny. Probably because you made a bigger deal about it than you needed to.
"Em, listen." You wave for your sister to stop and she thankfully does. "Our cabin... you can't talk about anything that happens in that cabin."
"Aww! But it-"
"Ah! Ah! ANYthing. So I'm not going to tell mom how you want to sleep naked with me, or show me your pussy..." Emma purses her lips and glances at the ground, meekly waiting for you to continue. "...and you're not gonna blather to Asha about how hard my dick gets. Got it?"
"What if I already told her?" she asks after thinking about it, her nose snootily upturned. She's probably being a brat, but she had the opportunity this morning, and it's very believable the way your sister runs her mouth. But you can't do anything about that.
"Then don't say anything else, okay? Or I'll toss you in the river while you're sleeping."
"I'd wake up first."
"Then I'll smother you with a pillow and then throw you in."
The two if you settle down and manage to come to an understanding, you hope. Some things have happened which shouldn't have happened, but neither of you are going to tell anyone about it. You threatening to tell mom should indicate how serious you are. Em makes idle threats like that all the time, but you don't. And maybe Mom lets Emma get away with a lot more than you, but you doubt Em checking out your cock while you're sleeping would fly. So unless you both want to be grounded for a year, keeping her mouth shut is the least Em can do, especially given how much of a pain she's been.
Back at camp, Em immediately races off to find Asha. You're about to yell at her for that, so quick to forget what she agreed to, when she throws a "Don't worry!" over her shoulder as she runs off. Easier said than done.
You spend the day hanging out in camp waiting for nothing in particular. Lunch comes and goes and you get pulled into a few family activities but being tired kills any aspiration to do anything.
The only interesting thing that happens is a dripping wet naked May stomping her feet through camp not even trying to cover herself. It is kinda funny. She complains to her mom that a fish stole her panties and then belligerently insists that someone go down to the river to "catch the fish" and get them back. Once it's made clear to her that her undies went floating down river and are long gone, May almost heads back to the river before she's shooed into the kids' cabin to get dressed.
If only you could ignore your sister the way the adults ignored May. They gave her an amused glance but didn't make a big deal about her nudity. Most hardly glanced at her. Meanwhile you can't seem to keep your dick down the moment your sister shows any skin.
It's hard to tell how much Emma wanted you to draw her naked and how much she was messing with you, but it sure seemed like a combination of the two. She all but outright asked you to draw her without pants on, and then took that way further by posing totally naked. So was she trying to get a rise out of you? Literally? Or was she doing something taboo for the sake of it? Either way, it sure feels like the kinda crap she does with Asha when those two run off together.
You don't see much of Em or Asha through the afternoon. It isn't until dinnertime that there's commotion that brings their whereabouts to light. Turns out Asha thought bush berries would be a tasty snack and ended up spewing in the kids cabin.
The adults sort things out but Asha is MIA the rest of the night which results in Em gluing herself to your side just as the party starts. Yep. That's your luck alright. Maybe you can learn from your aunts and uncles.