Jake talks about a real punishment in his post :
she swung [the cane] so hard that the first stroke hit me in my lower back, right on the bone. Normally, the first few I can bear, but this was a whole new kind of pain, and I involuntarily shot up like a rocket and let out a prolonged wail
Well, you didn't think all those pain toys were just for fun, did you?
Paradoxically, your partner might not hurt you too much because she loves you. But she might arrange for someone else to punish you severely if you screw up.
Yes, it depends on the nature of your relationship.