A Fervent Wish

About 10-20 years ago pants and shorts showing asscrack was much more popular among young women, not quite so much today but you still see it occasionally. I really, really, really wanted one of those young women to let me stand behind them and stroke my hard cock into their crack, touching them if allowed, or (almost as hot) just half an inch away, pointing at her crack without entering it. I want her to completely ignore me and do nothing sexual at all, even verbally. Just sit still as I stroke myself off towards the gap between her cheeks, then squirting my semen into her crack, watching it drip down under her panties.

A variation on this is if the woman is unaware, perhaps by being asleep (if awake obviously she'd be shocked pretty quickly), but that's nothing I actually want to do, just an imagined fantasy which would allow me to do this to many women. What I really want to do is for a woman to pretend she is asleep, or awake and unconcerned once I start coming. But either way, to do nothing to lead me on except to leave her exposed crack open to my gaze and my ejaculate.