Trapped in the Closet is a "hip-hopera" (as stated by creatorR. Kelly), the first songs/videos of which were released in 2005. Dozens of further installments ("chapters") have been released since. The songs tell the story of Sylvester (played in the music videos by R. Kelly himself) and the crazy characters he encounters as a result of a one-night stand.
It's become a cult classic, generally regarded asSo Bad It's Good. It's very clear from interviews that R. Kelly takes it perfectly seriously.