I post below a video by Fr Paul Nicholson, but before I do, I want to post this piece by St. Thomas Aquinas. He is a Doctor of the Church (probably one of the leading ones) and author of Summa Theologica, from which this quote is taken. This is from "the second part of the second part", question 33, article 4, reply to objection 2. It reads (in part), "It must be observed, however, that if the faith were endangered, a subject ought to rebuke his prelate even publicly. Hence Paul who was Peter's subject, rebuked him in public, on account of the imminent danger of scandal concerning faith and, as the gloss of Augustine says on Galatians 2:11, "Peter gave an example to superiors, that if at any time they should happen to stray from the straight path, they should not disdain to be reproved by their subjects."
Now the video.