Offline/Let your sister bunk with you
You go back and forth with her for a while, but you're too tired to fight. You open your sleeping bag with a groan and usher your sister inside.
She fits, barely. It's a good thing she's small. With you on your back she has enough room to lay next to you on her side, but the bag is far from comfy now. Of course that's not a problem for her because she promptly cuddles up into you, seeking protection after whatever ghost-riddled nightmare you likely helped induce. You recall dad complaining about Emma crawling into their bed at night but you didn't think she was still doing it. What a pain.
Since it's your fault that she's scared you resign yourself to the role of comforter. You wrap your arm around her and let her nestle her head into your body, her toes tucking under your leg. You've never shared your bed - let alone your sleeping bag - with anyone before. It's immediately annoying... but it is kind of nice to have someone cozying up to you and seeking your protection. It's nice to be needed anyway. And it's also good that your sis is over her little tantrum. But what ruins that sense of familial closeness is how little your sister is wearing.
Still donning nothing but her panties, Em's slim little figure presses against your equally uncovered side as your arm wraps around her bare back. Your hand naturally comes to rest very low on her back where you can feel the lace edge of her girlie underwear. That's not really where you want your hand, but you feel locked in place the moment she lets out a heavy sigh, Em appreciating our arm blanket.
Wanting her to be comfortable, you try to restrict your movement, but that only makes you feel more antsy and nervous. That physical tension is only made more awkward as your dick stirs from its slumber as well, your brain forcing you to recall your cuddly little sister sitting on top of you in nothing but the panties you're trying desperately not to fiddle with. An evil part of your brain tries to make you pull your stiffening cock out of your boxers, to rub out a quick one while she's sleeping, but you shoot down that idea. You have the worst thoughts sometimes...
By focusing on the sound of your sister's soft breaths, you let your dick settle down and eventually manage to drift back to sleep.
---
You awaken to the sound of knuckles rapping wood. You blearily look around before realizing that Emma is already opening the door.
"Rise and shine!"
"Daddy!" she yells, throwing herself at your father. "Last night was so scary!"
"Why, pumpkin? What's wrong?"
"I had nightmares about ghosts!"
"I see. Did they steal your nightie?"
Emma frowns in response to dad's weird joke then shoots you a grumbly look. Suddenly Dad is looking at you as well.
"Huh? Justice?"
Well this isn't fair at all. Did you really have to wake up to this?
"Nothing!" you bark to a question that wasn't asked, immediately on the defensive. "She kicked me!"
"Easy, Justice," dad replies. "No one's in trouble. Emma? What happened?"
"Well... yeah, I kicked him last night," she admits, her demeanor softening.
"I see. And then you took her bag away, huh? More or less?" He asks you, glancing around at the evidence strewn about the floor, her bag stuck between you and the wall. It's not how you remember it, but there are a lot of details you'd rather not share, so you keep your mouth shut.
Thankfully Dad isn't looking for a reply and keeps rambling. "I get it. Bit of a sibling squabble, eh? But you two ought to be able to get along for a few hours at a time when you're out here. You don't even have to look at each other the rest of the day while in camp."
"Yeah, you're right. It's all real straightforward. So since she's basically uncontrollable maybe you and mom should take her instead."
"Justice," scolds dad.
You smirk. "It's just a joke." But not really.
"I know you wanted this cabin to yourself but this is hardly a big ask. All you've got to do is sleep with her."
"Well, I did," you huff, alluding to something you probably shouldn't. "And she's still ridiculous." Dad just nods.
"Good. And no more kicking young lady. Unless you don't want to sleep with your brother."
Emma really thinks about that. Her glare has long faded and instead she looks at you with a degree of thankfulness. Despite your spat, you were the one who protected her from the ghosts last night, even if you're also the one who caused that in the first place. Once she comes to grips with the fact that you helped her she takes a step away from dad and clasps her hands together in a conciliatory pose.
"No, it's okay... I'm sorry for kicking you Justice."
"Really?" you reply, a little confused. "Uh... thanks. It's okay."
"Excellent," remarks dad proudly, perhaps crediting himself with this result. "Well... I'm glad to see you two can get along! Now, I only came out here to make sure you didn't miss breakfast."