Athina Onassis Roussel married Alvaro Affonso "Doda" de Miranda Neto, an Olympic athlete, in 2005, and the couple remains married as of 2015. Neto represented his home country of Brazil in five Olympic games, competing in the team equestrian sport.
Neto competed in the Olympics in 1996, 2000, 2004, 2008 and 2012. His Brazilian team won the Bronze medal in both 1996 and 2000. He has also competed in the Pan American Games and the FEI World Equestrian Games. Together Roussel and Neto co-own AD Sports Horses.
Neto was previously married to fashion model Cibele Dorsa, with whom he fathered daughter Viviane in 2000.