I had a weirdly analogous moment in HS when a girl I knew yanked on the back of my necklace and realized instantly that it was vaguely arousing to me. (Well, except I sort of knew her and she called me gross and I never admitted it in any way and still wish she'd actually have been into it.)
Lol same, a friend of mine in middle school did a similar thing to me. Like- she pulled on my ponytail really quick and hard, basically a "YAGA!" ya know? So my head snapped back and I made this little whimper/keening sound caused by surprise, but also a good amount of arousal. It didn't hurt for some reason, it just provided a pleasant sensation. Sadly my entire table heard it and I was teased for it until I graduated.
