5x19 - 3rd Rock from the Sun

Frank, a former student of Mary's, returns for a lecture series, making Dick jealous, and paranoid that he is after her. When confronting Frank, however, he hints that he is gay, but Dick misreads him and is convinced that he is hinting at being an alien. Therefore, Dick begins to regularly accompany Frank to Geoffrey's Lounge, which he thinks is an alien bar. Meanwhile, Sally, Harry and Tommy receive a visit from Don, who has just inadvertently foiled a bank robbery, and decide to use their superior knowledge to rob a bank themselves. As the episode progresses, each of the Solomons dons a costume of one of the Village People (Dick as the construction worker, Harry as the indian, etc). At the end of the episode on their porch roof get-together, they are joined by Don in his police uniform to complete the tableau, and the episode ends to a Village People song.