You beat Natalie's back and sides

You ask the sobbing student to take off her top and stand with her hands on the wall, just above head height. Her new boss immediately leaps up to assist, helping her back onto her welted soles and removing the required garment, before folding it as neatly as possible, considering the artistic shapelessness with which it appears to have been designed. Natalie shuffles into place, whimpering with each step sending lances of agony shooting through her feet. Unlike her bottom, her torso displays no trace of recent chastisement and you can just see the outline of her ribs rising and falling as she gasps for breath. Her nipples, like her breasts, are small, but they're stiff and relatively dark in colour, standing out in every sense.

When she's ready, leaning against the wall, you tell Minseo to stand to her side so that she can turn her head to allow them still to maintain eye contact. The younger girl moves very close, so that you're almost certain they're sharing the same breath. Then, from directly behind the trembling twenty year old, you run the tip of the rod over her supple flesh, choosing your target with appropriate care.

"Please may I have the twenty-fifth stroke, Professor," she asks, dutifully.

Her ribs make a tempting objective and you strike firmly, though not as hard as previously. Nevertheless, the reaction is pronounced, the centre of Natalie's body twisting violently to the side with an audible groan and almost colliding with her rival. You warn her that if it happens again, you will repeat the stroke and she tries to thank you, but is interrupted by the need to retch, pain starting to make her nauseous. Finally getting herself under control, she tearfully requests the next stroke and you proceed, putting it directly on top of the red oval shining like a beacon from the previous impact.

This time, she doesn't flinch, but a shudder runs through her whole body and she starts to gulp for air, the bruising of her ribs making it hard for her to breathe. You quickly check with your hands that you haven't actually broken any bones, even the light pressure you apply sending her chest into convulsions and making you think she may pass out completely, but a strained wheezing announces that she's through the worst and soon manages to ask for more.

You continue the pattern of three strokes to each area before moving on and although she's prepared, it still leaves her **** and snorting, short hair plastered to her scalp in the cold sweat in which she's broken out.

The next three smacks go higher up, just under her armpit and she copes relatively well, but the following set to the bottom of her rib cage is the worst yet, the combination of gagging from nausea and heaving for breath leaving her weakened and in danger of collapse.

The danger comes to pass on the first blow to her flank, roughly level with her kidney. Her knees fold up and she drops to the ground in an untidy heap, moaning and obviously looking away from Minseo, who immediately bends down to check on her tute-partner, their rivalry temporarily replaced by concern. You curse inwardly. You said that breaking eye contact would earn her an extra dozen strokes, plus whatever you add for the failure to remain on her feet and you're already short of time with the next set of students about to arrive for their tutorial. To top it off, it doesn't look like Natalie will be in any shape to give you a decent sex tip afterwards. You wish you hadn't decided on such an **** consequence for losing the debate, but salvation comes from the long-haired nineteen year old in front of you.