Misha hadn't been thrilled when her Dad remarried just after her 18th birthday. She understood that he was bound to move on some time, but it wasn't easy for her. She reluctantly accepted Harriet, her step Mum just to keep the peace, but they would never see eye to eye. They were just cut from too different a cloth. As long as her Dad was happy, she was willing to tolerate 'that woman' as she used to call her. 

On the positive side, she had gained a step brother. Tom was entirely different from his Mum and obviously took after his Dad. He was easy going, funny and clever - just like Misha in many ways. They were the same age and had a lot in common, particularly a love for fast cars. In many other ways they were different. Misha had her Mum's Lebanese complexion with startling blue eyes, luxurious long black hair and a perfect 36-24-36 figure, as well as an ass that both guys and girls dreamed off. Tom was a well groomed man, very fair haired, clean shaved and athletic.

Over the eight months that Misha had acquired her new family, she and Tom had grown quite close, in a matey sort of way; something she could not have envisaged a year earlier. There was genuine warmth between them, and they kept in touch, even through on a personal level, they led their own lives.

It was in the September of that year that Misha graduated from college and was excited for her Prom.

It so happened one day, a simple mistake set in motion a chain of events that would lead them to see each other in a very different way.

For a while, Tom had promised to let her check out his new baby, a Lotus Emira V6. It was a real monster of a car, with a top speed of 180mph. The college ball wasn't till 6 pm so she had time to do this and still have hours to get ready for her big night. Misha's car was in for service, so she took the 30 minute train journey and short walk to Tom's on the understanding he would give her a lift back. 

The Lotus was amazing. Tom had the top spec in ocean blue. Misha absolutely loved it and it was a proper adrenaline rush as they over took other cars - the road handling and torque were phenomenal. Its acceleration was just crazy, she was thrilled having the opportunity to 'open her up' on the country roads near his home.

They returned in one piece and Tom offered to make a coffee before they set off back to hers.

Tom had complained of a slight headache and took a tablet from the medicine cabinet, while Misha called up one of her friends to chat about what was happening in the evening.

Tom returned presently, Misha slipping into the next room, while he sipped his coffee. Misha became aware that her step brother appeared to be a little ill at ease.

"Are you okay Tom?" You look a bit flustered.

"I don't know what it is. I feel a bit weird to be honest."

"Sit down, and drink your coffee. You'll be okay."

Misha recalled the drive and enthused over the Lotus' performance and asked about coming another time to take it out again. As she spoke, she noticed Tom looking very uncomfortable, shuffling in his chair.

"Tom, you sure you're okay?"

"I don't know. Ooh shit."

"What is it?"

"I... I'm getting a boner."

"Wooah! Too much information, bro."

"No I'm serious. Ow! It's not you."

"Oh. Keep digging."

"No, I mean you're gorgeous but your my step sister. I mean, this is different. I didn't make it happen."

"Ha ha! I've heard everything now!"

"This isn't funny, I'm going to have to unzip my jeans."

"Shit, Tom. Can't you think of something? Think of a brick wall, that's meant to work."

Tom unzipped his pants and Misha gave a little shriek to see the tent of what was clearly a formidable hard-on in his trunks."

"Blimey Tom!"

"I know. I can't explain how it's happened."

Misha, mildly amused, asked if he'd taken some Viagra by mistake.

"Oh no!"

"What?!!"

Tom dashed off, holding his manhood and returned shortly holding a packet of tablets.

"I have, I've only gone and taken a fricking Viagra."

"Sheesh I was joking, why the blinking flip have you got Viagra at your age?!!"

"I haven't. Mum and your Dad were over last week, he must be using it."

"Really?"

"Whatever. What am I going to do? I can't drive you home like this."

Misha suddenly realised they had a real situation on their hands, and the clock was ticking. She couldn't miss her Prom night, and at the same time accepted that she had to deal with what was in effect a medical emergency.

"You're going to have to sort yourself out," observed Misha.

"I can't, it's really tender." 

Misha puffed her cheeks out and held her hands out in frustration.

"Tender! I can't believe this is happening. Today of all days," she chided, running a hand through her raven locks.

"Well I didn't do it deliberately," Tom admitted, sensitive to Misha's annoyance.

Misha checked the time. She was going to be cutting it fine if the situation didn't resolve, and she wasn't one to rush in getting herself made up.

"If you can't sort it out, I'll have to do it."

Tom winced and laughed nervously, at what he thought was a quip. But as Misha began to unbutton her top, he realised that she was deadly serious.

"What are you doing?"

"I know a bit of how Viagra works. It's effects are physical, but you still need to be turned on to ejaculate."

Misha unbuttoned her sleeve cuffs and slipped her top off, revealing a lacy bra and a delicious decolletage. 

Tom gulped, his values and emotions suddenly in dissonance, as she made to remove her bra.

"Misha, for pity's sake, your my step sister, we can't do this."

Misha licked her lips, nodding and was clearly not up for any kind of negotiation.

"Let me spell this out, Tom. If you make me miss my Prom, you're toast. I'll make sure your Mum gets to hear about what's happened. About how she's so gorgeous that my Dad has to take fucking Viagra. So you will get turned on. I will suck you off. And you will drive me home in plenty of time."

The way that Misha spoke only served to heighten his increasing arousal, which was now catching up with his state of priapism.

Misha unzipped her skin tight jeans, her matching pink panties so skimpy that the flimsy fabric barely covered the plump lips of her pussy.

"Take off your underwear and sit on that chair." Misha's voice was calm but with a tone that was not to be defied.

Tom was anxious, aware that he was out of options. He looked at Misha, as she reached round to unfasten her bra. His painful erection was now not just an inconvenience. It was accompanied by a quickening heart beat and dry mouth, as he gazed at her fantastic unfettered breasts. They were perfect; the areola delectably puffy.

He removed his trunks, his uncut cock a full eight inches of throbbing manhood.

Misha didn't mess about. She hovered over him and pushed her tits into his face, at the same time stroking her panty gusset across the tip of his cock.

Tom groaned as she brushed her nipples over his lips, her fingers stroking his dick with a feather light touch, making his heart miss a beat. Tom involuntarily ran his hands along the back of Misha's legs and squeezed her gorgeous butt cheeks. His male urges had quashed his earlier misgivings of the illicit nature of the situation and sucked her boobs passionately.

Misha was eager to get the job done, but was finding herself getting turned on, and had her actions not been born out of necessity, she didn't know how far things might go. 

Misha had a sensuality that she knew how to employ instinctively, and she brought it to the fore on this occasion.

"Come for me, baby," she whispered, blowing softly into his ear, before dropping to her knees.

Dragging a finger over his nose and down his front, she kissed the bulbous head of his penis. Tom gasped and watched in amazement, the feelings of pleasure making him groan as his step sister sucked him softly. Despite the urgency of the moment, she knew the circumstances called for finesse rather than haste, and performed her fellatio lovingly. Her head bobbed gently, as she took him inch by inch, using her tongue to perfect effect.

She drizzled a long line of saliva over his rigid member, using it as a lube and wanked him in a figure of eight before gliding her tongue around the glans. 

Tom's cock ached as Misha gave him the blow-job of his life, kissing, licking and sucking his cock with a focused attention but not so rushed that it wasn't blowing his mind.

Misha began to wank him rhythmically as she sucked on the top two inches of his wood, sensing that he wasn't far off, judging by his increasingly urgent moans.

She looked up at him and reached inside her panties, pushing two fingers into her now soaking wet pussy. Her tongue circled the head of his dick as she tugged him faster, her hand working the foreskin against the most errogenous part of his cock. Tom's leg's trembled against her body, as she sucked him harder until her step brother couldn't take any more.

His body jittered with orgasm and he let out a loud howl of pleasure.

Misha hadn't planned for him to come in her mouth but it just happened naturally. When he came, it was an explosion of cum. Misha was aware of her mouth suddenly filled with the salty sweet spunk. As she swallowed the first load, he came again and then again. His body jerked, his cock pumping until she had drained every last drop from his balls. 

Misha stood up, glancing at Tom awkwardly, the inappropriateness of the whole thing now coming home to her.

"Okay get your kit back on and let's go, please," she said.

ooooooo0oooooo

They barely spoke as Tom drove her home, breaking the speed limit for most of the journey. He dropped her off so that she was only just behind schedule.

Misha tried not to dwell on the events of the afternoon, but knew she now needed to navigate what was going to be a difficult dynamic between her and Tom. She had no idea how things would work out.

For now, she would put it behind her, be the happy but thoughtful eighteen year-old that she was and enjoy the evening with her friends.