I don't know if I qualify, but will apply anyway.

I had a tummy bug last weekend and laid down for a nap on the big bed. Woke a few hours later and walked across the room to slip into my sneakers again... wandered off into the kitchen and around the house for a few hours. Later returned to the bedroom and found much blood in the carpet! Was horrified and patted down both cats looking for a puncture site on either ... unsuccessfully. Eventually gave up and used an enzyme cleaner on the carpet. Anyway, I later kicked off my sneakers wondering how the cats managed that when I noticed that the tip of one sock (which I'd slept in) was sopping wet with blood! Eventually I found a tiny puncture in one toe and assume the toe had been 'in the wrong place, at the wrong time' as a cat crossed the big bed...

So I can't say it was painful as I slept through it, but perhaps this just means that the cats have me well broken in?