Both at once!

You grin and declare, "I don't just want one of you...I want both of you at once!" Kako looks at you oddly, then shrugs, and rubs some of her cum into her tits as she stands up. She rubs her cockhead along your face playfully as she moves off to the side, leaving a sticky trail. You can't wait to fist both of your girls at once. You don't know which you will enjoy more. Kako has a nice ass, far larger than any other you've seen, excepting Jennifer's. It's slightly tanned, and a bit saggy but very soft. Then there's the ass of the woman who is currently fistfucking your ass rather fast. Jennifer's ass is milky white, and gigantic. Yet it is firm, and thus not as soft as Kako's. It holds its nice shape without sagging, but still shakes when she walks.
Lost in your reverie, you wait as the girls get themselves ready for you. You assume Jennifer is holding everything up, as she seems to be obsessed with fisting your ass. You hardly notice it until it's too late. You don't notice as a few fingers slide in alongside Jennifer's fucking fist. Until the second hand begins easing its thumb in, you are lost in your fantasy. At that time, though, you feel yourself being stretched a lot once again.
"Hey, Jennifer don't put your other hand in!"
Jennifer replys, "I'm not." You feel yourself continuing to stretch.
"That's my hand," Kako chimes in. She jams her thumb inside of you, causing a momentary sharp pain. "You said you wanted us both at once, so I'm gonna shove my fist up inside of you so we can both fistfuck you at once...like you told us to." You sigh as you feel Kako working her fist into you. It's not so bad, Jennifer must have loosened you up further as she fistfucked your ass for the past 15 minutes. After you resigned yourself and stopped resisting and let them do it to you, your ass opened for her without any more pain.
"I fucked you fast, so your muscles are going to be really stretchy for a bit. Aren't I the best?" Jennifer sounds proud of herself. "Oh look, there are two fists in your ass now! Want us to fuck you with them for a while? You don't want to wake up tomorrow and have tightened up again. Although you can't help tightening up a little bit, if you don't keep your ass loosened, you will lose all the work we have done." Without waiting for a reply they start shoving their fists in and out of your asshole. You can't believe it doesn't hurt. Jennifer must really know how to work an ass...which figures considering she has the largest around! "How do you feel?"
"Loose," you respond. You barely feel the fists leave your ass.
"Jennifer, that's hot. Look how he is gaping!" Kako squeals in delight. You feel her spread your ass, then feel her plunge her face into your crack. She licks your gaping hole with enthusiasm. Then you feel Kako pull away, and after lubing her hands with her own semen, she double fistfucks you. You enjoy it this time, but don't feel as stretched. Kako's hands must be a bit smaller than Jennifer's, considering she is about seven inches shorter.
"Pfft, that's nothing. Jennifer, you come double fistfuck me. I want to be stretched a bit more by your larger hands while I fuck Kako's steamy pussy. Come here and get some cock, Kako." She welcomes the prospect of getting fucked, and withdraws her fists from your gaping butt. Kako hops onto the couch, spreads her legs and lifts her testicles up so you can enter her. She moves her cock up between her breasts so she can titfuck herself while you testdrive her pussy. You aren't disappointed. It is good and tight, and she has good muscle control and massages your dick nicely.
"Hey, keep your ass still for a sec if you want me to put my fists in you," Jennifer says, annoyed. You stop until she forces both of her fists inside of you. It's definately a stretch, even for your well-used gaping butthole. It takes her half a minute to work the extra girth into you, but you wiggle your ass to encourage her when it seems like she is going to stop and give you a short break. Well, you wiggle it as much as you can while having your cock up a shemale's pussy while at the same time having another shemale's two fists impaling your ass...or trying to get yourself impaled on those fists at any rate. Are they even shemales anymore? They have vaginas now. Hermaphrodites, maybe? Well, to you, they are your women...just with a little, er gigantic, bonus. You wonder what that makes you. Not gay, you don't dig guys. Can't be bisexual either, as that also requires liking guys. You figure you are just a normal guy who likes things freaky and enjoys playing with his ass, as many guys likely do secretly. You've seen bondage with girls fucking guys with strapons. The only difference here is that your toys are life-sized and intelligent. You moan as Jennifer finally gets her fists inside your anus. You just rest your head on Kako's cock as Jennifer fucks you hard with her fists, causing you to bounce back and forth on Kako, fucking her without any effort on your part. You lick Kako's dick where your head is laying on it. Kako tenses up and her pussy clamps down on you. You tense up as well, your ass attempting to clamp down on the fists fucking you, as your balls channel your semen.
Jennifer feels it in your ass. "I'm so proud! You've made so much progress! You are about to cum, and your ass muscles are so well loosened that all they can do is quiver! Here, I'll massage your prostate, it'll make you cum harder!" You feel the familiar sensation as your ass provides a powder keg for the spark of your orgasm.
You explode, and Kako feels the power of it spatter her insides. "Oh, I forgot..." is all she gets out, and she starts cumming herself. You can feel her balls churning under you. You have a long orgasm, but of course Kako keeps going after you pull out. You decide she will keep going for awhile, so you get up to walk around the other side of the couch. Jennifer goes along with you. You really like the feeling of walking around while so filled by her fists. You immediately notice Jennifer's gaze is transfixed on your ass; her arms are hanging limp. So you try to sway your ass a bit like you've seen women do when they catch you looking at their rearends.
Jennifer snaps out of it. "Hey, that's hot even though you aren't doing it right. I will have to show you how to do it right later. For now, try swinging your hip as you lift your foot, then stepping down hard, so your buttcheek sways and then bounces." You give it a try. Your right cheek swings out, then bounces and jiggles. It feels nice with her fists inside of you. "Yea, that's a good start. You will learn faster without me inside of you though. Once you get it that way, then we can practice with you being double fisted. Your nice ass-cleavage is spread all wide right now, so you can't get the correct feeling." You practice as you walk around the couch anyways.
"I like how it feels, and I like it even more since you can't take your eyes off of my ass when I do it."
"Well, you are blessed with a nice one, and it's even better knowing I stretched you this wide," Jennifer cooes.
You get around to the other end of the couch and watch Kako finish up from a different angle. After she is done a thought pops into your head.
"Hey Jennifer, you havn't gotten off yet. When are you going to?"