When a character says something that had to be censored, and they keep on talking with the censor for an extended period of time, so you know it was really bad.
Family guy: (Season 17, Episode 19: "Girl, Internetted"): Peter asks Meg if she has any talents, and she says she does, where she starts to speak and then gets censored for several seconds, while she makes several suggestive hand gestures. After she stops talking, Peter starts to cry, and then she continues. After, he says that he will be taking her door off its hinges.
B99: (seven 7 finale episode): A very pregnant Amy (like, her water has already broke, but with the blackout hitting New York she wants to stay and help as a police office) is dealing with contractions, and then in come Scully and Hitchcock, trying to help (they usually mess stuff up). She is not taking it, and so swears for a good solid 5 seconds, in such a way that even Rosa, the police office who usually is unfazed and not shocked by a lot, is surprised, her eyebrows rising and her jaw hitting the floor. When she stops swearing, Hitchcock himself swears for a good few seconds as well.
(Bonus points on the reaction of the people hearing it)