After his group disbanded, Dino played professional tennis and semi-pro football; he got his pilot's license; he studied medicine and joined the National Guard. He started calling himself Dean Paul instead of Dino. He changed into a blond. He developed a spectacular physique.
And he acted, of course. Not a lot -- he was too busy. 7 movies, mostly in roles as playboys or a woman's illcit lover; some guest spots on tv shows (including his Dad's Dean Martin Comedy Hour), and some "as himself" appearances on talk shows and game shows.
The Greatest American Hero). He played Dr. Billy Hayes, a young scientist who travels around in an ice cream truck with a group of mutants with weird powers. 15 episodes appeared during the 1985-85 season, and another in 1988. A lot of homoerotic buddy-bonding (notice the number of people who can't keep their hands to themselves in this photo), and not a lot of heterosexual machinations.
He died in 1987 when the small plane he was flying crashed. His son, Alexander Martin, is also an actor.
See also: The Gay Rat Pack; Cesar Tells about His Hookup with Desi Arnaz Jr.