Offline/Ignore the kids and try to talk to Nicole
You're not as worried about the others as you are about Nicole. You really should feel worse than you do for your part in this, though the thrill of having worked your cousin's raw pussy, however brief it was, is likely clouding your judgment. But you do have enough presence of mind to know you should apologize, even with your cock as stiff as it is.
Calmly lifting May off of your lap, you make sure to grab Nicole's glasses off the floor before talking to her.
"Hey... I've got your glasses," you say, sitting down next to her bunk. Nicole ignores you, head under her pillow, hiding from the world. Not sure what else to say, you look up and watch as Asha rubs her hands across your sister's bare chest to make fun of you and Wade, Em cackling at this until she remembers she's supposed to be moaning. But Em also wants a turn and makes Asha take her shirt off so the besties can grope each other's flat tits in turn.
"You, um... you were really..." Your words stumble to find footing, somehow unable to string an apology together. After some stammering, you do eek out a single sorry, but there's still no acknowledgement from Nicole. Laying down next to her you find you can't peek under her pillow without lifting it so you decide to give her another minute to herself and glance around the room to pass the time.
The moaners aren't going to stop anytime soon it seems. Emma has started groping Asha's crotch in addition to her chest and Asha hilariously returns the favor, the two of them thinking they're so funny. Meanwhile Brayden wants to show off his cock monster and waves it around in front of his sister. That encourages Beth to pull her panties down to revisit her own doodled privates. Yulia wants to participate in show and tell and suddenly doesn't care who sees what's under her nightie, lifting it high to show off Beth's work, an incomplete upside down bunny with ears scrawled along her pussy lips.
Feeling like you've been patient enough, you lift one side of Nicole's pillow to check on her and get her attention. She's face down, eyes closed, her cheek smooshed against the floor, but her arms are tucked under her and her expression looks strained. The moment she notices you, she pulls an arm free to snatch her pillow back and grumbles at you to go away.
"I'm just trying to apologize," you explain before watching two pairs of siblings chase after each other swinging nighties and undies over their heads. Brayden is snarling and swinging his legs, his cock monster whipping about. Beth is wiggling her arms out in front of her like tentacles while Yulia hops about with one arm up, the nightie in her hand waving like a flag. May is right there with them, panties over her head, but she's asking someone to give her a monster since she doesn't have one..
"Oh yeaaaah!"
"Awww yeah!"
"Ohhh yeaaww!"
Emma and Asha are still groping and moaning in jest but Emma keeps sticking her hand inside Asha's panties. Asha giggles awkwardly but lets her do it, though she reluctantly reciprocates. Emma takes care of that reluctance a moment later, dropping her own panties and forcing Asha to grab bare pussy with every grope. Asha goes along with it, giving Emma license to dive into her friend's panties, but they're bordering on this not being harmless fun anymore.
But while all this is going on you're starting to get mad at Nicole. Maybe that's because of how horny and frustrated you are, but she was the horny one before. She was the one talking about how hot she gets while dancing and how amazing it was to be felt up by everyone. All you had wanted to do was get her top off. She's the one who started moaning until she embarrassed herself.
"Hey! Would you just talk to me?" You pull the pillow off of Nicole again, trying to talk to her. She's not happy about that. She actually grunts at you. Spinning off the floor, propping herself up on an elbow, she angrily flicks her hair out of her face.
"Oh my god, Justice! Just leave me alone and let me cum already!"
"Huuhmmnnngh!"
Nicole yelling at you might have held everyone's attention if the funny noise from Wade hadn't come right after. You all turn your heads in his direction as he spews his load into the panties he stole earlier. Nicole and Beth loudly voice their disgust while the younger ones laugh, playtime quickly resuming. The moaners can't pass up this new opportunity to mock someone, Emma insisting Asha "jerk her off". Asha's fist repeatedly pulls away and taps Emma's bare mound while Em keeps her hand down Asha's panties, the two of them overzealously moaning and shouting, practically falling over one another.
WIth Nicole finally taken out of a private moment, she disgruntledly accepts her glasses from you. It takes you a moment to notice that Nicole sat up in her bunk to yell at Wade. Since she's still naked, her beautifully petite titties came into view the moment she righted herself, her sleeping bag unzipping enough for the front to fall away from her body. Of course when she looks back at you through her glasses she finds you staring at her.
"C'mon, Nicole. It was an accident," you start, unsure what you're apologizing for now, distracted by your current thoughts. Her bottom lip sticks out as she scoops up the front of her sleeping bag in her arms to cover herself. Dammit. You tried to look up quickly, but it was pretty obvious where your eyes were. "I just... I'm sorry, okay? I didn't mean to do that. It was just really hot and I thought..."
You trail off, not sure if your words can make a difference. Pulling her legs up to her chest, Nicole wraps her arms further down her sleeping bag to grab her knees and keep her front covered, lowering her face into her bundle of bunk until just her eyes are peering over at you. Her expression, what you can see anyway, is soft, more curious than angry. It seems like she's waiting for you to continue.
"Well... you looked like you were into it. And if you weren't, I'm sorry. I just... I couldn't stop thinking about you dancing."
"Dancing?" she repeats.
"Yeah. I saw you dancing outside earlier and you were talking about how it gets you so hot and then all of a sudden you were sorta dancing naked on your back while we were coloring you. You looked really good with your head swaying and your arms all twitchy. So good that... well, if your boobs made you that hot, then I was hoping your vag would... y'know. I dunno..."
Your excuse at least keeps her interest, even if you're reaching. Most of your interest is on her back, much of her figure exposed behind her after she sat up and partially unzipped her bag, her crayola'd rounded fair skin uncovered all the way down to her bum as she leans into her knees. You swear part of you wanted to talk to her just because you knew she was naked inside of her sleeping bag, though you knew apologizing was important. Being able to again drink in part of her naked body is a better outcome than you could have hoped, even if she hates you for the rest of this trip.
"It was... kinda... hot..." she admits, mumbling past her sleeping bag.
That's nice to hear. Nicole's face is still so flush and her hand comes in to push up on the bridge of her glasses when you notice the swirly mix of colors coating a few of her fingers. No one was coloring her hands and you can only think of one place she could have so easy collected so much ink from her body. It's not like it takes any imagination when she admitted to it a minute ago. Weirdly she's only slightly better than Wade in that regard, at least having the decency to get herself off in the privacy of her bunk instead of in plain view of everyone. That may even be part of why she ran away, not wanting to risk going "all the way" in front of family.
"Yeah. I, uh... yeah," you agree, not so subtly adjusting the boner in your shorts, inviting her eye. She grins, looks away, returns for a second glance, then looks back to the room, suddenly aware of the escalating inappropriateness around you.
Emma and Asha are still standing next to each other but they've stopped making so much noise. Asha's hand is cupping Emma's crotch but is otherwise quite still, while Emma's hand is very much not. Your sister is smiling broadly while working her digits inside her bestie's panties, carefully observing her cousin's expressions of pleasure. The girls are gazing into each other's eyes, sizing each other up, perhaps unsure of how far is too far, or no longer caring.
Those two aren't really playing anymore, but the rest of the room isn't much better. Yulia is busy doing headstands with Brayden, him holding her upside down so his sister can finish drawing the bunny face on her pelvis, all three of them naked. Yulee has her legs spread wide, Brayden hooking his forearms around her thighs to help steady her, which means he's staring straight down at her split open pussy, and he's staring pretty hard. Yulee also gets to stare, Beth down on her knees with her legs apart in front of her cousin's face, her own colorful privates positioned squarely in Yulia's field of view.
None of that holds a candle to Wade however, hiding in a dark corner. May is standing in front of him but it's hard to say what they're doing until she shifts to widen her stance. He's got a finger half buried in May's squishy little cunny to "help him" draw something on her, but he isn't doing much drawing. He keeps pulling his finger out of her to give his cock a few strokes before reinserting into her tiny pussy that she's holding open for him.
Nicole notices this about the same time you do, but she's the first to act on it. She doesn't say much, just stands straight up out of her sleeping bag, marches across the room butt naked (fitting in nicely with your other cabin mates), grabs May's hand, and leads the girl back to you.
"Get in," she orders, more exasperated than angry, opening up her bunk.
"Oh, okay... will you make me a monster?"
"No." That's not the answer May wanted. She starts whining as Nicole climbs into her bag beside May, a tight fit for two. "Shuddup and go tuh sleep," she slurs, a combo of drunk, upset and tired.
"Uh, yeah. Good idea. Lights out," you agree, standing to kill the lantern that has let all of this inappropriateness go on for so long. There are a couple groans, but when you grab a flashlight to lead people to their bunks they generally comply.
When you lay down in your own, you immediately strip off your boxers and beat your meat as quietly as you can. The problem is that your sister is right next to you, and not only are you not anywhere near as shameless or twisted as Wade, you don't want to make a mess of your bunk either, not to mention get caught masturbating next to your sister. So you stop yourself almost as quickly as you start.
"Em..."
"Shhh."
Asha and Emma let out whispers and sighs back and forth for some time, lots of rustling going on between them. You have half a mind to tell them to knock it off, but your other half wins out as it pictures your sister's hand shoved inside your cousin's panties. After carefully peeling open your sleeping bag, you slowly stroke your cock next to them, their soft murmurs driving you on until you nut on your stomach. That desperately needed release instantly gives your brain permission to fall asleep.
What a weird vacation...
Though not usually an early riser, you again manage to wake up before any of your cousins. You slept like a rock last night, which means you wake up in the exact same position you nutted in, on your back with your cock out and streaks of cum having run down your sides. That sure is embarrassing. You hope anyone who had to get up last night to pee didn't notice you like this.
Cleaning yourself up with your discarded boxers, the only thing of yours nearby, you then gingerly move across the room to grab a fresh pair from your bag. One glance around the room tells you that hardly anyone is in their sleeping bag, the cabin especially stuffy after all the activity last night.
Nicole is the first to grab your attention. Her sleeping bag is bunched up at her legs, perhaps kicking the heat trap off of her during the night, which reminds you that she took May to bed without either getting dressed, the younger cousin cuddled up against Nicole's bare side. May's head is partly resting on Nicky's chest and nestled by Nicky's arm but her mouth is less than an inch from one of her big cousin's puffy nipples. It seems so unlikely, but the idea that May was softly sucking Nicole's young titty throughout the night gets your balls churning, as if the sight if Nicole's long lean figure and colorful pussy wasn't already.
That's almost as bad as discovering that Asha fell asleep with her panties around her knees, your nude sister spooning her side, both girls out in the open. They were sleeping right next to you, too. That's quite the compromising state to be found in. Yulia rolling halfway out of her nightie is one thing (which she has again managed to do) but you don't feel it's possible for Asha to have innocently pushed her panties down her legs while sleeping.
Weirdly none of that holds a candle to how you find Beth. She did put on panties before laying down atop her sleeping bag, but you're pretty sure she didn't squirt lotion on her face after. Runny ropes and drops of semen streak across her features, the serenely sleeping girl unaware that someone nutted across her face at some point during the night. That's a far more disturbing sight than cousins cuddling without clothes on.
Since it wasn't you who did that - at least you're pretty sure it wasn't - that only leaves a couple of suspects in your cabin. But unless an adult packed a DNA test kit you doubt the guilty party is going to fess up to doing it.
Although your dick isn't complaining as you inspect your young cousin's facial, there's no way you can leave Beth like this. You carefully dab and wipe her face and neck with the closest bit of clothing laying around. You really don't want her to wake up and have to explain what it is you're doing, crouching naked above her half erect, so you aim for "good enough" so you can put something on already.
But is that all you're going to do? Everyone else is in quite a state as well. Part of you wants to help out your cousins to provide them with some amount of modesty, but there's a lot to do to make that happen. You might be able to wrangle Nicole's sleeping bag over her and May if it's not caught under them, but pulling up Asha's panties or down on Yulia's nightdress is going to be challenging without accidentally incriminating yourself. Probably better to let this be.
Leave your cousins and head out to see if there's coffee
Last night was embarrassing enough, try to give your cousins some dignity