What is the ruling on men wearing tight trousers and short shirts that reveal their 'awrah, and is a woman who inadvertently sees them sinful?

It is disliked for a man to wear anything that defines his 'awrah (private parts), and it is not permissible for a woman to intentionally look at a man's 'awrah. If her gaze falls upon it suddenly and unintentionally, there is no sin, but she must avert her gaze, based on the hadith of Jarir ibn Abdullah: "I asked the Messenger of Allah, may Allah's prayers and peace be upon him, about an accidental glance. He commanded me to avert my gaze."