Let 'er rip. Study after study after study has shown that deer cannot recognize human scent from urine. Too many hunters I respect on here and elsewhere that pee off their stands all the time and continue to take world-class bucks.
Here's one I got a couple years ago... Sixth time I'd seen him, just couldn't get a shot. And I pee off my stand all the time. If the pee bothered him, he'd been long gone before I ever had a chance to put an arrow through him...