I think Riley is finally trying to mark things and actually pee while standing on three legs. I thought he'd never get to that, which didn't bother me at all.
Twice yesterday, I turned around to see him off-balance while peeing (though on all fours). He's usually beside me or just behind me when we walk, so I missed the attempts to put his leg up. Once, there was pee a good foot up on a stack of tires he was beside (the guys at the tire business were probably less than thrilled, and I apologized). I figure he had to be on three legs to get it up there.
So I haven't *seen* him in action yet, but it seems that Riley, at almost 16 months old, has decided it is time to pee like a big boy dog... all over whatever he can get to.