Although Forstmann never married, he adopted two boys, Everest and Siya, in the 1990s after meeting them at an orphanage in South Africa. In 1994–1995, Forstmann was involved with Princess Diana. Between 1999 and 2000, Forstmann was rumored to be dating Tracy Richman, Elizabeth Hurley, and her friend Birgit Cunningham. In 2008, he dated Allison Giannini, a 38-year-old Actress who was in Mission: Impossible III. Finally, from 2009 until his death, Forstmann was dating Padma Lakshmi, the Indian-American host and judge of Top Chef.