What should I do if the 'awrah of a worshipper appears in front of me during the Friday sermon due to pants that slide down from the back revealing the 'awrah?

The prohibition of speaking during the Imam's sermon on Friday has been reported, even if it is to forbid an evil, based on the Prophet's (peace be upon him) saying: "If you say to your companion on Friday, 'Listen,' while the Imam is delivering the sermon, then you have engaged in idle talk." So, if a Muslim sees an evil, he should remove it by gesturing, not by speaking, such as by hand signals or placing a finger on the mouth. This is what Imam Ahmad explicitly stated and what a group of the Salaf held. Speaking is permissible between the two sermons for a benefit, or before the preacher begins the sermon, or after its conclusion, because the ruling is restricted to the time of the Imam's sermon.