The challenge begins

Thwack.

The first spank landed without warning on Mitchell's unprotected backside, and caused a high-pitched yelp of surprise. The spank was hard and sharp, and almost propelled him forward were it not for the stands they were fixed to.

Tanya looked across and saw the grimace on his face. I'm next, she thought, her body already trembling slightly in anticipation of the impending blow.

She looked ahead, and set her jaw in a determined fashion. She wasn't going to show any pain or fear to Rachel, she'd deny her at least that.

She instinctively clenched her naked buttocks, and then closed her eyes as she her heart began to race.

And yet no blow came. She opened her eyes after a few seconds more had passed, and for a brief crazy moment, she hoped that maybe the machine had...

Thwack.

The machine landed it's first blow on Tanya's unclenched ass, and all thoughts of denying Rachel any sign of pain went out of the window.

"Ouch!" she cried, as her stinging ass cheeks sent shockwaves through her senses even after the impact.

Tanya looked out on to the audience as her mind raced with the pain of the very first strike, and saw in their eyes a strange mix of interest and pleasure. Interest at seeing how these two newcomers to the kinky arts could handle such a formidable machine. Pleasure at the erotic mix of sexuality and pain.

For Tanya, who had never even dreamed that such a club could exist before tonight, it felt like she was being stripped of any identify and just turned into some sexual play toy for others to objectify and experiment on. It was - to her straight-laced mind - one of the most shameful feelings she'd ever experienced. And Rachel had ensured that Tanya had experienced an awful lot over the past week or so.

It had only been a few days since Tanya's backside had received Rachel's tender loving care via the black dildo, and the first strike of the spanking machine had already reopened the lingering soreness that Tanya still felt from that.

Mitchell knew his still-sore ass was up next for punishment. He tried breathing in quicker, to see if that would make the pain somehow less. He'd counted the number of seconds between his first spank and Tanya's, and had already forgotten about the random nature of the blows. So he was still preparing himself mentally when the machine suddenly sprang into life again.

Thwack.

"Shit!" Mitchell called out, caught off-guard. His ass was now burning, even more so than his face. He'd never been spanked in his life, other than a few playful strikes from Tanya when he'd teased her a little too much. This was nothing like that.

He too made the mistake of looking out into the audience, and groaned as he realized the kind of exhibition he was putting on for these people.

Tanya flinched, and squirmed in the stocks.

There was no loud cheering or laughter from the audience, and in a strange way this was even more disconcerting. No, these people weren't like the crowd at Mitchell's milking. The quiet, intense focus on their humiliation actually managed to make the shame even worse. There was no noise to lose yourself in, just the singular sense of white-hot soreness coming from their spanked derrieres.

She steeled herself for another hit, and found that she was holding her breath. She couldn't couldn't hold her breath forever though. It was as she was expelling the air in one long gasp that the machine chose to deliver its next verdict on Tanya's helpless backside.

Thwack.

"Arggh!!"

The random delay was what made the machine so diabolical. The uncertainty of the next strike, combined with it's inevitable impact and the ache coming from their bottoms already, was causing Tanya and Mitchell to strain and tense their bodies so much that they were exhausted just from predicting the blows.