If you can learn to relax it will prolong the sensation, I first started noticing this when I was seven, but I've only met a few people who react in the same way. It is pretty awesome sometimes.
Well never knew it was like a proper thing. The paintbrushes sort of work.
Prefer it when girls gently stroke the back of the neck. It introduces it and well far more plesuarable.


. But even better is when im in bed and cant sleep, she will lightly run her fingers up and down my back...that just puts me in heaven and within mins im out cold.