Sitting comfortably

Laughing at the misfortunes of others isn't nice, I know. But. Well, it amuses me a little just now. The dynamic of a spanko + non-spanko relationship is quite a tricky one and I often come away from our 'special time' feeling unfulfilled.
The problem is that SO is just too soft-hearted. A spanko in need of a spanking is looking for a SPANKING, not a token smack, but SO doesn't like to inflict damage (even when not inflicting damage is what hurts).

So, I'm there in the bathroom half an hour later with my bum pointed at the mirror looking for any sign of marking. A little trophy bruising is a rare treat.
Then on Friday morning there was the chance of a little kid-free fun time and we went for it. In deference to SO's interests we opted for spank-free.
Then at the moment of greatest mutual excitement something went twang deep inside SO's back and everything had to stop. A torn muscle we think and poor old SO has been in agony ever since.
What's funny about that? More ironic than funny ha-ha. Three, nearly four, days later and SO cannot sit down (or bend down, or stand up or do much really). Three days without being able to sit down? I should be so lucky.