Crystal walks in

The door suddenly creaks open and a familiar voice reaches your ears.

"So, care to tell me why the doctor was here?" Crystal says, crossing her arms, her gaze so intense it could bend steel.

"Ehm... We-I-They..." Sarah tries to explain herself but she is unable to formulate a sentence.

Crystal sighs. "It's what I think it is, isn't it? You fucked him senseless."

"No! I-Well, I didn't-We did-Doug please say something!" She says, looking at you, tears forming at the edge of her eyes.

You gulp, then pretend to cough. "I'm just feeling under the weather, really. And Sarah was helping me."

Sarah's eyes sparkle with gratitude, then a smile appears on her lips. "Yes! Exactly!"

"So then, why did the doctor have a drainer with her? A used one?" She taps her foot in annoyance. "I've been young too, you know? I'm not going to be angry, just tell me what happened."

Sarah's smile immediately disappears. "Fine, we... my friend and I may have had some fun with Doug." She looks up only to meet her older sister's disapproving gaze. "We didn't **** him or anything! It's just... You have no idea how good he is, we couldn't resist."

Crystal raised an eyebrow. "Give me the details." Sarah obeys. Crystal's expression subtly shifts while your younger sister tells her tale, from angry and disappointed to amused, and finally to intrigued.

"My, my, Doug! You had quite the adventure. I think I know the Mexican girl, her sister goes to the gym with me. If she's half the woman her older sister is, you manage to handle quite the monster, little bro. I really want to try your technique right now, but contrary to somebody here, I have the self-control necessary to recognize you are in no condition to indulge me" she concludes, throwing an ugly stare to Sarah, who could only look down, ashamed.

"I think some punishment is in order, don't you think?" She asks you. Punishment? For Sarah? You look at her. A part of you would not mind seeing her punished, she did take advantage of you while you were recovering, but another part knows all too well that you did not exactly resist the girls in any way, if anything you eagerly participated.

Sarah does not say anything, she is too busy staring at the floor, her muscles tense.

Just when the silence is becoming unbearable, Crystal smiles. "Why the doom and gloom? I just meant to say that you did all of that for them, and you did not get anything in return, it's not fair. So Sarah, you should fix this, how about giving your brother a blowjob instead?"

Both of your jaws fell to the floor simultaneously. Sarah was a proud futanari, and giving head was the males' job. You can see her brain fighting back storm of emotions, she only barely manages to stay still. And yet, to your surprise, she gets closer to you and slips her head under the bedsheets. You remain still, unable to react, while you feel your sister taking your underwear down and wrapping her fingers around your dick.

Shivers of pleasure spread through your body, as her fingers pump up an down your hardening cock. She has no trouble pleasing your comparatively small male penis: You are above average for your sex, but nothing compared to them. Soon enough, you feel her tongue moving up and down your sensitive skin. A manly squeak of pleasure leaves your lips, making Crystal smile.

Encouraged by your reaction, Sarah gathers her courage and takes your head into her mouth. The warmth and blissful pressure send you to high heaven, you can barely hold back your orgasm. And yet, it is a losing battle, your dick rarely gets this kind of attention, so there is little you can do to prologue that blissful sensation.

Soon enough the dam breaks. You arch your back as a flood of pleasure washes over you. Your hips move on their own as you thrust your dick into Sarah's mouth, shooting your load into her. After a few interminable seconds, your climax ends, and Sarah gets out of the bedsheets. She makes a show of her tasting your cum before swallowing, giving you a wink for good measure.

"Good girl! That's how you do it. But now we have a new problem" Crystal says, pointing at her own cock. "Come on, Sarah, don't make me ask. I'm sure you do not want mom to come to know of this and hog Doug for herself for the rest of our lives, right?"

Two jaws hit the floor again, but to your even greater surprise Sarah gives little resistance. Were they having some fun between themselves already? Your sisters are a lot kinkier than you thought. That or Sarah is secretly a huge submissive and cannot resist Crystal's dominant vibe. Or both really.

Sarah drops to her knees and frees Crystal's cock. Your older sister looks down with a pleased look, she does not move a muscles, leaving everything to Sarah. The younger sister takes Crystal's balls into her mouth, one at a time, while running her fingers along her shaft.

Soon enough, Crystal's footlong dick is at full mast, standing proud above Sarah's face. But the younger sibling does not waste time and takes her head in. This is the first time seeing someone else blow a futanari, so you find yourself at the edge of your metaphorical seat, eager to garner some tips on how to do the job better. To your surprise, however, Sarah struggles to get very far, her mouth and throat simply cannot take that huge dick. Is that why she called your equipment magical, was being able to take futanari cock to the hilt rare?

Low moans rise from Crystal's throat, as Sarah does her best to tame the beast. Your sister lasts far longer than you, she takes her time to enjoy her younger sibling's mouth. You notice Sarah is hard as well, one of her hands pumping up and down her own shaft.

After another deep moan, Crystal taps her sister's shoulders. Sarah is startled and takes her cock out of her mouth, just in time for Crystal's orgasm to hit her right in the face. Long strands of semen shoot out of the older sibling's dick, painting Sarah's skin white. You realize this is also the first time you see the full output of a futanari, and it is just overwhelming: Sarah's face is completely covered, huge drops run down her skin and clothes, her hair is getting saturated with it too, and it keeps coming! How the hell were you able to take so many loads into your stomach?

"Oh I needed that! Thanks Sarah" Crystal says, giving a nice headpat to her sister, who manages to visibly blush even with the thick coat of cum on her cheeks. Your older sister then looks at you: "Don't think I'm not going to try you out too, mister!" She says, but then adds "And don't go overboard, ok? You know how crazy futanari can be, You need to keep your head on your shoulders and not think with your ass." Her words are of genuine concern.

You nod and you are finally left alone. What a crazy week.