THE EMPEROR OF ICE-CREAM by Brian Moore. 250 pages. Viking. $4.95.
Seventeen-year-old Gavin Burke was watching his nubile sister. She threw her legs over a sofa arm, exposing cream white thighs and pink knickers. "Nice legs, hot stuff," said the Black Angel. "Stop that. She's your sister," replied the White Angel. Black Angel: "Remember last week, going past the bathroom? You looked." White Angel: "You're diseased. Degenerate." Black Angel: "Stop being so serious, I just said they're nice legs."
Poor Gavin. The time is the late '30s, and the angels talk so much that...