Call it a day or change tack?

Spank her legs

You change hands and move the strap downwards, still swinging quickly from side to side, but now hitting thigh, rather than buttock. Helen can't seem to decide whether to wail or sob as you roast the more sensitive flesh of her sturdy legs. Left and right, you slap her with the heavy leather, reddening and bruising her pale skin, which you suspect has not received a thorough spanking for many months, or even years.

The blonde's thighs are quivering, but there is nowhere to go in order to avoid your rapid blows and the tenderness builds inexorably to a crescendo of searing agony quite at odds with the casualness of your movements. Helen is now weeping helplessly and you could easily increase her suffering by flipping her over and taking the strap to her belly, breasts, inner thighs or even more intimate areas, but that is not why you're here and, to be frank, you know lots of prettier and younger women that you would enjoy reducing to sobbing wrecks far more.