Recently social concerns over the indecent language use in YouTube videos. This study investigates the relationship between the frequency of indecent language use (specifically, slangs and swear) contained in YouTube video and its performance indices, such as exposure (view-counts) and post-exposure satisfaction (# of ‘Likes’). Specifically, eight YouTube channels in three genres (game, politics, and sports) were selected; about 100 videos that were uploaded in recent two years were randomly sampled; and subtitle, view-counts, and the number of ‘Likes’ in each video were automatically scraped. After counting the number of slangs and swears utilizing crowd-sourced online lexicon of Korean slangs and swears, regression analyses were conducted. Results show that YouTube videos containing slangs and swears, compared to those without them, show slightly higher number of ‘Likes’ across nearly all channels, but frequent use of slangs and swears severely erodes the number of ‘Likes’. In the case of view-counts, similar patterns were observed weakly for a few channels. Discussions over the social concern over the indecency on YouTube were provided.