Gunnar Eric Nelson is an American musician, singer and songwriter. In 2005, Nelson became a cast member of Celebrity Fit Club (US TV series) 3, after actor Jeff Conaway left due to drug related problems. In June 2015, Gunnar and his family appeared on ABC Television's Celebrity Wife Swap opposite Vince Neil of Mötley Crüe. Nelson is the son of musician Ricky Nelson and actress Kristin Harmon. He is the identical twin brother of Matthew Nelson, and brother of Tracy Nelson and musician Sam Nelson. His paternal grandparents were Ozzie Nelson and Harriet Hilliard from the television program, Ozzie and Harriet. His maternal grandparents were football player and sports broadcaster Tom Harmon and actress and model Elyse Knox. His maternal uncle is actor Mark Harmon. From Wikipedia, the free encyclopedia