Fasteau is currently married to Anne Gerard Fredericks, an artist, art historian and former Wall Street professional specializing in the Japanese and other non-US equity markets.
Fasteau was an investor and partner in Sereno Properties, the developer and owner of hotels in St Barts and on Lake Como, Italy.
A controlling interest in Sereno properties was sold to private equity firm KSL Capital Partners in 2023.
Fasteau is an investor in and serves on the board of directors of Oxford Performance Materials, Inc., an advanced materials 3-D printing company that manufactures FDA-approved replacement vertebrae, eye sockets and other in-body bony structures from a high performance polymer.
Fasteau is the author of The Male Machine (1974) that argues that the overly macho, John Wayne idea of masculinity is destructive in both personal and public life.