Damn, that's got to leave psychological scars
I usually try to resist, and have become quite good at avoiding wood after a couple of girlfriends who liked to tease in public. That said, I was in a club getting frisky with my girl and got wood, and an old chap wandered up, pointed at my crotch, went 'wahey!' and wandered off with a big grin on his face
. A little embarrassing, but made me laugh!
Also, baggy jeans and long tops tend to work wonders