Delirious' Father is a unknown and a unnamed character from the video: GTA 5 Next Gen Funny Moments Ep. 53 (Droidd Pooing, New Home, Flying Glitch & Tutorial!).
Droidd and Lui caught his said father hostage in his car, and told Delirious about it, then his father jumped out his car; falling down on the hard road. Then being deceased.