What is the ruling on a male child urinating while standing?

It is recommended for a Muslim to urinate while sitting, as it provides more concealment, and urinating while standing is disliked unless there is an excuse. It was reported from Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) never urinated except while sitting.

In the Maliki school of thought, it is recommended to sit for relieving oneself if the place is soft and clean. It is permissible to stand if one is secure from being seen. However, if the place is soft and unclean, sitting is prohibited to avoid soiling one's clothes, and standing becomes obligatory.