Going Pee, Needing to tinkle, seeing a man about a horse, My back teeth are floating, do a wee, Go Number 1, and answer the call of nature are all great ways to say you need to Urinate. As a matter of fact people have been using "polite" and "amusing" ways of excusing themselves to go to the restroom.
Well if you don't need to go number 1, but you don't want to let your buddy go by himself, you can use The Lil Whizz Kit! It's quick release valve will make it look exactly like you're peeing! It comes with 1 heat pad to get the Medical Grade Synthetic Urine to a life-like and realistic temperature.