From Wikipedia, the free encyclopedia Denis George Mahan (born June 15, 1950), better known as Deney Terrio, is an American choreographer, former film actor and one-time host of the television musical variety series Dance Fever from 1979 to 1985. In 1991, he sued Merv Griffin, the show's producer, for sexual harassment; the US$11.3 million case was later dismissed. Terrio achieved fame as the dance coach and choreographer for John Travolta in the movie Saturday Night Fever. During his heyday w ...