Jack graduated from the University of California at Berkeley with a double degree in Fine Arts and Sociology. He studied fashion design in Parsons School of Design in 1991 after moving to New York. He opened a menswear store called "Jack" in New York City's West Village. He worked for Tommy Hilfiger starting in 1997, then the Slates brand. Since around 2003 he has been the design director at Weatherproof Active Wear.
Jack is also a competitive swimmer with national recognition. He has three All-American titles, and in the summer of 2006 set a national record in the breaststroke leg of the 4x50 meter medley relay. He is open about his positive HIV status. He was diagnosed in 1990.