Kindly refer to the following link(s):
What is the Awrah and who can see the Awrah?
Are the Knees & the Navel part of the Awrah for Men?
What is a Man's awrah in front of mahram & non mahram women? (topless)
Can men be shirtless in front of other men?
Are the Knees & the Navel part of the Awrah for Men?