Modern critics of Christianity have repeatedly drawn attention to the recurring trope of the blessed watching the damned being tortured in hell. It appears most forcefully in the famous passage from Tertullian’s De spectaculis that was quoted by both Gibbon and Nietzsche, as well as in later theologians like Bonaventure and Aquinas (who didn’t have the excuse of being persecuted).
This theme appears to be mostly absent in City of God, where Augustine nonetheless insists on the reality and the appropriateness of eternal damnation for the majority of human beings. There is a strange element of his treatment of eternal punishment in Book XXI, however, in that he responds to critics who don’t believe that a physical body could endure endless suffering by pointing to all the many natural wonders he had experienced or heard of. He mentions the salamander, which supposely lived in fire, as well as more obscure examples such as the imperishability of cooked peacock flesh (something McDonald’s should look into). There’s even a passage in which he anticipates the Insane Clown Posse’s immortal line: “Fuckin’ magnets, how do they work?” The ostensible message is clear — if God can do all this amazing stuff, how can you doubt that he could make a body that was able to endure eternal torture? Yet the subtext is disturbing: by insistently associating eternal torture with all these cool things, he is implicitly counting it among God’s marvellous wonders.
Hence the theme of enjoyment of and fascination with the tortures of the damned appears even here, in submerged form.
An und für sich 
Don’t forget the part where he praises the ability of the human body to produce flatulence that can mimic various melodies. God is amazing!
That is a classic passage, but it occurs during his investigation of what pre-sin sex might have looked like. The immediate context of the flatulence example is his response to critics who doubted the possibility of conscious control of the sexual organs.