>"Oh, I hope I see dolphins! That'd be just lovely!" Fluttershy nearly squees behind you as you steer the boat.
"Mmm," you answer, trying to stay awake.
>Your family had only just landed late yesterday at this tropical vacation spot, and Fluttershy had already woken you up early so that you could take her out on to dive.
>"And clown fish! They're so cute, sleeping inside their little sea anemones!"
"Lucky fish; I could be sleeping right now, too."
>"Um, sorry for waking you, but I just couldn't wait, and I don't have a boating license."
>You look over your shoulder at your remorseful sister and sigh.
"It's fine. I can just take a nap on the beach later," you tell her, getting a small smile from the girl. "You'll just owe me one, is all."
>"Anything! You're the best big brother for doing this!"
"I am, aren't I?" you quip, turning off the engine. "We're here, by the way. This reef is a ways out, so you don't have to worry about other divers scaring the fish."
>"Oh! Just let me get my suit on!"
>While you hear rustling in the back, you look at the climbing sun and squint.
>It's not too bright now, but depending on how long you're out here, you may regret not bringing a hat and sunscreen.
>With how much Fluttershy likes animals, you'll probably be making your way back to shore by noon if you're lucky.
>Great.
>"Um, Anon?"
"Hmm?"
>"I can't get my wetsuit zipped up."
"What?"
>You turn to see your sisters large, creamy breasts nearly popping out of her wetsuit and blink.
"Ah jeez, Fluttershy? Did you not check the size."
>"I thought it was big enough," she says demurely.
"Not for those melons," you say, standing. "Great, now we're gonna have to go back to the rental shop and get a different one!"
>"But then I won't have as much time to play with all the little sea critters," the voluptuous girl moans. "Can't you just help me zip up?"
"That wet suit isn't a TARTIS," you reply dryly, only to groan as she gives you puppy dog eyes. "Fine, let me see what I can do."

>Ignoring the jerk your cock gives as Fluttershy eagerly thrusts her chest out, you grab hold of the zipper and give it an experimental tug.
>Her breasts compress a little, but more force just has the soft skin being pulled by the fabric attempting to come together.
As she hisses in discomfort, you grumble, "We could probably manage it if we had some lotion or something to get 'em slick. You bring any sunscreen?"
>"Um, no, I forgot," she mumbles, a slight blush coming to her cheeks.
"So did I," you say, stepping back to look at the problem from a new angle.
>All you really see is your sister's phenomenal rack practically spilling out of the tight black fabric.
>Your cock gives another twitch, and you're about to send it a mental reprimand, when it suddenly sends you a plan of it's own.
>No, that couldn't work.
>It's crazy.
>But Anon Jr. is pretty convincing.
"Okay, I think I've got an idea," you say, getting your sister to perk up.
>"You do?!"
"Yeah, we needed something to lube up your tits, and I've got the only lotion for miles," you answer, starting to smirk as you unzip your pants.
>As your cock flops out, Fluttershy gasps.
>"Anon! What are you doing?!"
"Same thing we used to do when you were thirteen and I was fourteen," you answer, stepping forward to bring your stiff cock near her face. "What? You forget our special fun time where we'd pretend to be different animals mating. It was your idea, after all."
>"B-but Mom and Dad caught us and said we could never do it again..."
"Well, Mom and Dad aren't here, and it's for a good cause," you rationalize, slapping your member against her left boob. "Come on, you want to see the cute fishies, don't you?"
>"M-maybe I can just dive like this."
"And risk getting a jelly fish sting across all that exposed flesh?" you say, looking incredulous. "Nope, it's either this or we turn around now."
>The girl bites her lip, then slumps.
>"Fine, for the sea animals."

"Great!" you cheer, bringing the tip of your dick to her lips. "To start, you've gotta get it slick some, then I'll handle the rest."
>Face beat red, Fluttershy looks from your eyes to your member before slowly leaning forward.
>Your hips jerk a little as you feel her tongue touch directly below your cock head, jolts of pleasure shooting up your spine as she angles her head and runs her wet muscle down your length.
>Damn, it had been so long since you'd last fucked your sister that you'd nearly forgotten, but now the memories were flooding back as she returned to the tip and wrapped her lips around it.
>Seems the memories are coming back to her, as well, as she sucks your member into her mouth like she's been doing it everyday for years.
>As her tongue swirls around the underside of your cock, you notice her thighs rubbing together.
>You grin, ideas of what you'd be doing later in the hotel room filling your imagination.
>She does owe you one, after all.
"That's enough," you tell her as she slips a ball into her mouth. "As much as I want to finish on your face, you need it somewhere else right now.
>"Huh?" she breathes as she looks up with half-lidded eyes.
>The look becomes disappointed when you pull your cock away, only to lower it to her breasts.
"Let's get these nice and slick," you mumble, grabbing your sisters shoulders and thrusting your cock into the crevice between her tits.
>Damn, this wetsuit really is tight judging by how much pressure your member is engulfed in.
>You don't let that slow you down, however, as you start fucking your sister's cleavage.
>Catching on, Fluttershy grabs hold her massive mounds and presses them together, squeezing your dick even harder as she lowers her mouth and sticks out her tongue.
>As your cock peaks out, it brushes against the moist muscle, adding just a bit more pleasure to the amazing titjob you are getting.
>Too much maybe, after that good sucking, as you cum in a couple minutes.

>The first rope of spunk fires just as your cock pops out from between her boobs, coating her tongue and lips before rolling down her chin.
>You pull back and let the rest release between her heavenly mounds and slowly bubble up out of the crevice like an orgasmic volcano.
"Mmm, there we go," you moan as she brings her hands up to the oozing jizz and starts rubbing it around. "get those knockers nice and slick."
>You pull back, your dick flopping free from the confines of her jogs for you to stuff back into your cargo shorts, and bend your knees to be on her level.
>Reaching forward, she moves her hands away as you suddenly grab the zipper and give it a harsh tug.
>She moans as the fabric comes together, enclosing her massive breasts within alongside a healthy load of her brother's cum.
>Following through with the motion, you run your finger up her chin to collect the dollop of semen there, which she happily opens her mouth for.
>Sucking the seed from your finger, she swirls her tongue sensually around the digit, eyes closed in bliss.
>As your pull your hand back and finger free, she follows it, intending to give you kiss before you poke her forehead to stop her.
>She opens her eyes to see you smiling cockily.
"Well, your wetsuit is on properly. Aren't you gonna go say hi to all your fish friends?"
>She blinks a few times before her eyes go wide and she stands.
>"Y-yes! Of course! Thank you, Anon for helping me," she says, blushing furiously.
>She quickly moves to the edge of the boat and takes a deep breath.
>Right before she jumps in, you hear her whisper, "I hope the water's cold."
>You chuckle and move to the side, taking a seat on the railing so that you can keep an eye on your sis.
>Wouldn't do for her to get eaten by a shark, after all.
>She probably smells pretty appetizing right now.