Ildefonso married Salvacion on August 18, 1960. He was a devoted and loving father to his seven children- Antonio III, Maria Cristina, Lyndon, Mario, Maria Elsa, Maria Victoria, and Ildefonso Jr. His love extended to his 14 grandchildren, Antonio IV, Gerimae, Ildefonso III, Sahlee Mae, Cornelio Jr., James, Gabriel, Von Riel, Alex, Ricaela, Sean, Sage, Skieler, and Harper; and to four great grandchildren, Princess Antonette, Anthony Shawn, Jamelo, and Antonious.
Ildefonso spent most of his time playing bingo, solitaire, and solving crossword puzzles. He enjoyed spending time with his family, singing karaoke, reading World War II history books, and was fond of playing music loudly. His favorite song was My Way by Frank Sinatra, which he would sing to his grandchildren and eventually became a song held close to the heart of every member of the family.