So I could use a little advice or something.
My son, who's three, is potty trained, but in possession of a three-year-old bladder. He *loves* to pee. Hey, who doesn't? Enthusiastically shouts, "I need to PEE!" and runs off and does it; trees (favorite), short toilets, tall toilets, urinals (second favorite), whatever. And I tend to drag him all over tarnation to places that may or may not have terribly accesible restrooms.
Now, I've repeated the mantra that we only pee on trees when there is no way we could possibly get to a bathroom in time, like when we're in the woods, etc. I Make sure we go before we leave. I ask if he needs to go when he starts doing the pee dance. Talked about private parts being private.