As a teen I did that back in the Dream Time, before family, before wives or even girlfriends. We were in the foothills by Bragg Creek and we found a stream and all drank our fill. Within hours we all had the squirts!
The lucky kids tied up all the stalls at the youth hostel. I wasn't so lucky, I was about 100 yards back in the bush, leaning against a tree, trying to do my business without getting any on me. The Out House Poet is correct:
No matter how hard
You wiggle and dance
The last one of all
In your pants.