Well if it's being printed, either the pisser is following orders from the bloke with a chokehold on his knob to stop and start, which some men find difficult to impossible, I'm assuming that the free hand (is there a free hand?) is holding a stiff card or a maybe a notebook to momentarily diffuse the stream, similar to morse code with a candle, hell why an I being such a priss? The thumb of which ever hand is most further up the shaft can block the urethra, or the free hand itself, if there is a free hand.
I'm not necessarily saying that it's a question of length that makes two hands necessary, but touched penises want to try to tuck into their owners belly button if they can reach, so it requires some strength to keep the bellend at right angles to the rest of the body and piss off into the distance at targets.
