What does IWHBYD stand for on the skull in the Halo series?

The acronym "IWHBYD" stands for "I Would Have Been Your Daddy" in the Halo series. It is a reference to an easter egg in the games, where players can unlock a special skull called the "IWHBYD" skull. This particular skull makes rare dialogue and phrases play more frequently during gameplay. The origin of the phrase itself is not entirely clear, but it is believed to be a playful reference to a popular phrase used by Bungie developers during the creation of the Halo games.