Who's is this famous crotch shot?

I always thought it was Mick Jagger.....but no......it's Joe Dallesandro,

who hung out at the Factory with his brother--who was, incidentally, Andy Warhol's chauffeur...while their mother was in prison for auto theft.......small world, isn't it? Incidentally, Dallesandro did not pose for the white underpants shot beneath the "jeans" shot......that was Warhol's lover-of-the-moment.....Jed Johnson!