Open English Wordnet
(n)adulterousnessThe quality of being adulterous, involving sexual intercourse by a married person with someone other than their spouse.“He consequently interprets his own behaviour in sociobiological terms so that, having slept with his ex-wif Charlotte in her current marital bed, he is unnerved not by the adulterousness of the act, which is routine for him, but by the infringement of male territorial boundaries.”