Wudoo' is not invalidated by that. We have already listed, in the answer to question no. 14321, the things that invalidate wudoo'. A man's seeing his own awrah or that of someone else is not one of them.
The Standing Committee was asked (5/270): is wudoo' invalidated simply by looking at naked men and women, and is wudoo' invalidated if a man looks at his own awrah? They replied:
Wudoo' is not invalidated simply by looking at naked men and women, or by looking at one's own awrah, because there is no evidence to that effect.
They were also asked (5/283): can a Muslim touch the Mus-haf or pray if he has looked at his own awrah when he was doing wudoo'? They replied: Yes, looking at the awrah is not one of the things that invalidate wudoo'.
Reproduced from Islam QA