I get it! You're eager for your story to be the hottest, most arousing piece of fiction ever conceived by the mind of Man. (I'm not being sarcastic: been there, done that.) So on page one, your 6'5, 220 lbs (all muscle) protagonist has a 10" cock and can cum like a firehose 6 times an hour. He runs into a supermodel—no, two supermodels! They have flawless hourglass figures, huge HH-cup tits, and the tightest pussies on the planet. They're dressed like sluts on the prowl and they're dripping wet. The instant the 3 of them see each other they all fall in lust, and 2 sentences later they're in a hotel room having the literal best sex ever. They enthusiastically engage in every sex act known to man, invent several that aren't, and repeatedly faint with the intensity of their orgasms. Your superlatives have superlatives. Excellent! ...But now what? How do you raise the stakes from here? Where do you go next when your story starts by standing on the peak of Everest? Leave some room for escalation! Of course your sex story should (probably) be hot from the get-go. Your thriller should be thrilling, your horror movie should be scary. But leave some headroom! When your action hero protagonist finally goes up against the Big Bad, it needs to be a more intense fight than the ones against the legion of mooks he waded through to get to this point. When your on-again, off-again couple finally get their happily-ever-after scene at the end of act 3, it needs to be happier than the first 7 times they got together. After your step-son diddles his step-mother for the first time, don't immediately transition into fucking 24/7, and make sure at least one of them is full of doubt and self-recriminations afterwards, or you'll have no incest taboo left to play with for the rest of the story.
There is room for immediate gratification - that what Porn Without Plot (PWP) is - but the problem is trying to write something engaging that lasts beyond a scene or a chapter. There's nothing wrong with starting strong like "Bobbie Jo screamed louder than that time she landed cunt-first on a parking bollard as Big Mack planted his hundredth bastard in her waiting womb." - the trick is to then go on from there and do something with the character that tests or develops their skills, ability, morality, characters, etc. in some way. If Big Mack wins the Cumite in chapter 1, in chapter 2 he may be faced with entrance to the Cosmic Cumite, where he faces off against sexual demigods from across the galaxy. So starting big is fine, but aim bigger.
This is my pet hate and probably the most common mistake I see on CHYOA. All to often I see the first two paragraphs covering what should take more than half of the whole story. Story arcs are thing, like wise character arcs, and once I discovered this it completely changed the way I write.
Also consider de-escalation. Start out strong, keep the ball rolling and the fire blazing. But when the ball hits a wall, when all that's left is embers, you gotta ask yourself "What's next?" Or rather, ask the characters. When you fuck so good you see God in his glorious, supple flesh, you don't really have a choice but to introspect a little, do you? And how do your characters feel, upon achieving Nirvana, after climbing the summit? Do they reach for the stars next, or simply walk back down? Maybe skip over some time, years or so in whatever direction you choose, to a time when such a feeling is but a fleeting dream, nostalgia or imaginaton more than concrete reality. Tldr: Do not be afraid to fall from grace, rise back up again to face the world with the sun on your back and the wind in your face.
