They both failed to meet the required standard

"I think…I should have been able to hold out longer, Professor, because…Lorelei, er…she wasn't quite as skilled as maybe she ought to have been—but she didn't know she was supposed to be practising this, so I don't think it's fair to blame her entirely."

Lorelei looks as though she wants to say something, but you have heard enough.

"Since you are both at fault, you will both be punished. Johanna, you'll spending the next three days naked, but for now you can make a start with the nettles while I deal with Lorelei."

This turns out to be easier said than done, as she has to crawl carefully to the edge of the table and then gingerly lower her still-throbbing cheeks onto the unyielding surface, before arranging herself painfully into the right position to start. Johanna reaches out to pick up the first of the remaining nettles and jerks her hand back with a yelp, momentarily looking for evidence of the sting her fingers just received before returning to her tortuous task, whilst you unhook a thin, whippy cane from the rack on the wall.

"I'm very sorry, sir," says Lorelei. "Please may I receive the first stroke."

You tap the cane across her nipples, causing a flinch and a shudder; clearly her **** melons are exceptionally sensitive, especially the stiff pink nubs. You raise the rod to commence and lay the first stripe of fiery agony across the tender pink aureoles, just below where her nipples jut outwards.

Her whole body stiffens, mouth open in a silent scream as a red ridge appears right over both globes, the tip of the flexible cane having wrapped round the side furthest from you. It takes a moment for her to recover enough to thank you and ask for the next, her voice already breaking in anguish.

The next three blows land in the same region, by which time her responses are barely-intelligible croaks and her boobs are trembling so much that you couldn't guarantee hitting her nips again if you wanted to. Instead, you widen the target area, cruelly scourging the sensitive undersides with stroke after stroke. One benefit of their prodigious size is that they can take a dozen lashes from the slender rod without overlapping. You notice that the extra speed with which the end of the cane is travelling is causing the greatest trauma and walk casually around the completely hysterical girl, her green eyes wide and glassy with panic, so that you can inspect the crescent of blackening weals forming on the far side of her breasts. Just in time, you think, as you're sure that many more would have broken the parchment-thin skin.

In order to even up the welts, you begin to flog back in the other direction, causing an unrelenting crescendo of torment that leaves the teenager thrashing her head from side to side in a vain attempt to cope with the monstrous pain. You have no intention of awarding extra strokes for this, because although the cane you chose was deliberately light, two dozen blows to such a **** target is still a formidable punishment.

You return the wicked instrument to the rack whilst Lorelei struggles to regain control of her tortured body, boobs striped from side to side with a mass of livid corrugations that you're sure will act as a warning to all young ladies who see them. You're pleased to note that Johanna hasn't been distracted from her own assignment by all the commotion. Perhaps your earlier spankings for voyeurism have had the desired effect.

The Asian nineteen year old is having a harder time applying the nettles without another girl to assist, but her squeals and whimpers demonstrate that the procedure is still highly effective.

"Johanna, when you've finished, could you help Lorelei put on some sun screen while I write up your placard?"

"Aaagh, yes, aah, Professor, ah-ah-ah-as soon as I can."

It only takes a moment to fill out the placard, but some time longer for Johanna to complete her onerous task, with increasingly intense reactions to the building irritation in between her legs. By the time she's finished, Lorelei has recovered somewhat and dragged herself off the table, breasts vying with buttocks and pudenda for the cause of her greatest pain.

"May I help Johanna put on some sun screen too," she sobs, "because she burns almost as quickly as I do?"

You give your approval and sit back to watch the two naked beauties taking turns to rub sun screen into each other's skin, with much gasping and yelping to attest to how sore a lot of that skin currently is. Yesterday, this would have been a performance that would have filled your imagination for months, but amazingly it's actually one of the less exciting experiences of the afternoon! As you look on, you think there's something not quite right and ponder whether to add another restriction to the punishment.