Voyeurism :  (noun)

1: perversion in which a person receives sexual gratification from seeing the genitalia of others or witnessing others' sexual behavior

active algolagnia, algolagnia, algolagny, amphierotism, autoeroticism, bisexuality, coprophilia, curiosity, curious mind, curiousness, exhibitionism, fetishism, ghoulishness, heterosexuality, homoeroticism, homosexualism, homosexuality, incest, incestuousness, inquiring mind, inquisitiveness, interest, itch for knowledge, lesbianism, lively interest, masochism, meddlesomeness, mental acquisitiveness, morbid curiosity, narcissism, necrophilia, nosiness, officiousness, paraphilia, passive algolagnia, pedophilia, prurience, prurient interest, prying, sadism, sadomasochism, sapphism, scopophilia, scotophilia, sexual inversion, sexual normality, sexual preference, swinging both ways, thirst for knowledge, transvestitism, tribadism, tribady, zooerastia, zoophilia,