It is permissible to uncover one’s private parts to the extent required, just as they are uncovered when relieving oneself.
Accordingly, if a man bathes alone—even though he has something with which he could cover himself—he may bathe in the nude, just as Moses bathed in the nude,1 and Job,2 and as is reported of the Prophet ﷺ when he bathed on the Day of the Conquest,3 and in the bathing narrated in the ḥadith of Maymūna.4
The second category of looking—for example, looking at the concealed adornment of an unrelated woman—is graver than the first, just as wine is graver than carrion, blood, and swine flesh, and the ḥadd is inflicted on the one who does it. As for those other forbidden things, if someone consumes them while deeming them lawful,5 he is subject to discretionary punishment (taʿzīr), because the human soul does not crave them the way it craves wine. Likewise, looking at a man’s ʿawra is not desired as looking at women is desired, and looking lustfully at a beardless youth falls under the same ruling.
The scholars have unanimously agreed on its prohibition, just as they have unanimously agreed on the prohibition of looking at an unrelated woman—or even a female relative—with desire. …
He goes on to say:
Thus, looking at beardless youths falls into three categories: