Amalgamation
You actually don't mind how it all works, but its not like you'd ever say that aloud.
(Written in second person, without spoken dialogue)
Your name is Cera. You're an amalgamation. That pretty much means you can copy certain physical traits of others.
The catch, though, is that you can only take traits of people you have oral sex with, while you have oral sex with them.
Naturally, you're fairly talented with your tongue.
Its not that you mind that part, its just that finding someone with desirable traits who will let you stick your face in their crotch isn't exactly easy to do, especially since there have been times where things have... mutated in unexpected ways. You recall a time when you went down on a girl and you came back up with a snake tongue, despite her being mammalian (as far as you could tell, at least. You've been surprised before though). You got fabulous hair and a cute as hell nose out of it, though. She seemed... oddly satisfied as well.
But you're getting better at it though, really!
Right now, you're a humanoid male, about 5'7", blonde, and fairly average looking, somewhat androgynous in appearance. You've had this for a while, and you've become a bit bored with it.
You explain this to your friend, a large anthropomorphic Gorilla. He just flashes you that classic grin of his, and tells you to come to his place tonight at seven. He'll handle the rest.
You two have known each other for as long as you've been in this town (at least three years if you remember correctly), and he's never let you down before when you need a change, so you accept his offer.
That night you stand outside his building, waiting for him to let you in. After a quick trip up a flight of stairs, you reach his apartment, where he greets you in the hallway. He says he invited a few of his buds over to play video games, and that you could have your pick.
You laugh, and tell him that he sounds like some sort of mad scientist. He just pats you on the back and ushers you in.
Along with your friend the Gorilla, there is also a Pig, a Bull, a Lion, a Wolf, and a Crocodile, all males this time. The only thing missing was an avian type body, but that wasn't much of a concern since the most you ever borrow from them is coloration.
All in all it was a good spread, like you had expected.
But while you weren't just interested in physical traits, it pretty clear that your friend was trying to subtly suggest a body type, judging from the stomachs on these guys.
You find yourself breaking them all into components. Horns, limbs, tails, ears, eyes, snouts, skull shape, height... you know its probably rude to view other people as parts to use, but its something you do subconsciously. Eventually, you start to get a good idea of what you want.
One by one, they each introduce themselves to you. You stay polite, and try not to let slip that you're gonna end up sucking them off and copying various body parts of theirs. Though, you have an inkling your friend might have informed them of that. He's clever, and he's crafty, but he's honest to a fault.
Your friend takes off his shirt, complaining about the heat, and you get a good look at his torso. He's fairly chubby, and his belly hung over his shorts in a way you've never really noticed before. You avert your gaze before he notices you staring at him and assumes you're breaking him down too.
Throughout the night, pizza is eaten, beer is drank, games are played, and you occasionally sneak a glance at your friend's bare stomach.
When he goes to get something to drink, he calls you into the kitchen. Curious, you come, only to be pinned against the wall by his bulk. You're eye level with his pecs, his belly pressed into your chest. You manage to tear yourself away from the sight, and look up at him, baffled.
He lets slip another grin, and admits he's noticed you checking him out. You start to apologize but he cuts you off.
He's not mad, in fact, he tells you he gets off on being this big. With a more mischievous look, he adds that he likes to pin people to walls as well.
You shift a bit, and say that you don't really mind being pinned, either. You feel something brush up against you, and with a bit of shock, you realize its his dick. You can't really say anything, considering how hard your own has become as well, but you're still fully clothed while, as you can tell, he's either naked, or at least in his boxers. You rub his stomach and ask him if he wouldn't mind letting you borrow a few traits of his. He picks you up and carries you over his shoulder to his bedroom. You shoot a sheepish grin at the other guys, who all give you thumbs up, to your utter mortification.
You can't tell if he's well endowed, or crouched down low, but either way as you head to his room, you notice that there is a... trail behind the two of you. You can feel his face heat up as you let out a chuckle.
He places you on his bed, and moves to remove your clothes, looming over you. For a second you wonder just why he needs to do that, if you're just going to give him a blowjob, but he lays on the bed and bares himself to you, making some really mood killing jokes about how you're gonna ravish him and to be gentle with his fragile form.
In an effort to shut him up, you get to work. It takes a while, as sucking on a dick isn't easy when you're laughing, but you manage to regain your composure long enough for your abilities to kick in.
You focus on his torso and arms, then realize that until you get a proper pair of legs, you'd look ridiculous. Your narcissism wins out and you end up setting for taking his build, while keeping most of your looks the same. You'll probably end up overwriting most of it later this evening anyway.
You continue to work at it, feeling your body change as well. Its a strange sensation, as if your limbs had fallen asleep, but through your whole body. You feel something brush up against your swelling torso and you become aware that you took on his cock as well. You then realize why he left a trail. As aroused as you were, you're fairly certain you'll do the same too.
He shudders, and you move to remove yourself, but he holds you on as he orgasms. Your mouth is flooded with cum, and you begin to swallow, if only because you couldn't possibly hold it all in your mouth until he let you up.
The more you swallow, the more he lets loose. You feel yourself getting full, and you realize that you're continuing to take on his traits, but multiple times over.
By the time he's done, and lets you up you're both panting, and you're now a few inches taller than him, and several pounds heavier, most of it settling in your gut.
He lets out a laugh, sitting up and patting you on the back. Halfheartedly, he apologizes for holding you down, but then adds that it did you good, appearance wise.
You're slightly offended, but let it go. You have a good base to start on, and you suppose it isn't so bad.
He moves a huge hand under your belly and begins to stroke your dick while you think, calling it his way of repaying you. Your mind blanks from pleasure, and next you know, you're laying on the bed, staring up at the ceiling. You breathlessly give him your kudos, and he pats your bulging stomach, which jiggles in response.
Since your clothes no longer fit, you borrowed a pair of his boxers out of modesty, despite his insistence that remaining nude would be easier.
You tell him that until you get everything the way you want, he'll have to wait to check out your dick, which causes him to turn red.
In the living room, the other guys were in various states of shock and curiosity. They tell you that while your friend had indeed explained to them who, rather what you are, seeing it in person is still amazing.
Its your turn to blush now. You tell them its just what comes naturally, which isn't too far from the truth.
You tell them that you'd like to do the same to each of them, if that's alright. They agree, out of curiosity, arousal, drunkenness, or a combination of the three.
You decide to go in order of weight. Your friend was interestingly, the lightest of them, followed by the wolf, the lion, the gator, the bull, and the pig, though the bull was the tallest.
They were all in their boxers, and close to, if not already hard, so you just had to get to work.
From the wolf, you focused on his legs, though your hair ended up turning the same shade of gray, and you got a bit heavier.
From the lion, you went for the hair, a rich gold in color, long and thick. (you admittedly giggle when you think that) but ended up with the same happy trail on your stomach as him, and feline eyes. Your ears got longer and pointier, but you chalked that up to just another random mutation.
From the gator, you take his teeth, and tongue. You also take care not to accidentally bite him. Your eyes turn green, but you think that it goes well with your hair. The claws on your new feet get longer, and you end up with a bit of an underbite, but again, you ignore it.
From the bull, your take his muscle and tail. You feel yourself growing horns, but from the forehead, rather than the temples. They arch back along your skull and end in a similar tapered point as his do. Your ears get a bit of fuzz on them, thankfully its light and mostly matches your hair and belly.
Finally, from the pig, (who later corrects you that he's a wild boar) you take his snout, tusks, and body mass. Your vision blurs a bit and you realize that your eyes have changed for some reason. You end up with his olive skin as well, which actually looks pretty good according to the others.
As you finish, you immediately rush to the bathroom to check your eyes. They are hazel, and the pupil is shaped like a four pointed star, or an elongated plus sign.
Locking the door, you remove your boxers and check your cock and balls. Its thick, its long, they're full and fairly well sized. And its all ready to be 'tested'.
You briefly give in to your primal urges, and as you orgasm for the second time this evening, you involuntarily let out a bestial roar.
You're enhanced hearing picks up chuckling from the living room, the others obviously aware of what you just did.
You clean yourself up, and forgo the boxers, joining them all in the living room once more. Your voice is now deep and rough, and you are much taller than the bull, and clearly heavier than the pig. With a cocky grunt, you wedge yourself on the couch, grab a pizza and beer, and declare that you're taking on the winner after the round on the game is over.
You decide this is probably one of the better bodies you've made. Your gorilla friend seems to agree, as he gives you a thumbs up.