dirty minded

exceptionally prone to seeing the scurrilous, sexy, or kinky aspect of everything; obsessed with sex; prone to seeing sexual overtones to nonsexual behavior. A dirty minded person may be hypocritical and unctuous, but read filthy motives into the acts of other people. For example, in the movie "American Beauty," the military officer wrongly assumes that his son's interactions with his neighbor are homosexual, rather than commercial--projecting his own repressed sexuality onto others (with deadly results).