I would very much like to see Whumpee handcuffed to a chair and unable to stop Whumper as they slowly tighten coils of rope around their body. Loops of rope tied around their ankles and knees and thighs, binding them securely to the chair. Their mind being forced to accept the increasingly restricted movement, their breathing speeding up rapidly with each loop tied off. Rope pulled tight around their stomach and ribs and chest, maybe a few loops around their neck, the coarse rope biting into their skin as it's secured to the back of the chair, forcing their head just slightly back. Biceps next, arms pulled together behind them and cinched tight, then tied at the elbows and finally their wrists as the handcuffs are removed. Left to sit, completely bound and immobile, under Whumper's gaze and at their mercy.