Serenge scare me greatly, but sweing needle don't bother me at all. When I was little I stepped on one(My parents sew alot- my mother is a seemstress). It didn't hurt and I barely felt it, but it went into the joint of my big toe deep. I sat down by my gramma and pulled it out, only for her to spaz and franticaly appologize. it took me a while to convince her it was fine.
It was kind of funny. It only bothered him when he had to take the thread out. Pretty thick thread too, not a single strand. I could imagine that it would feel funny...