The character was portrayed as a shallow, sex-obsessed person who thought about nothing else.

sex-obsessed 是由 sex（性）和 obsessed（沉迷的）组成的复合形容词。obsessed 来自动词 obsess（使着迷），加上 -ed 表示状态，意思是"沉迷于...的"。 sex-obsessed 表示"沉迷于性的"，形容一个人对性过度关注或痴迷。