A form of unlawful sex discrimination at work primarily perpetrated by men against women. First recognized by the US Supreme Court in 1986. Defined as unwelcome sexual advances, requests for sexual favors and verbal or physical conduct of a sexual nature. Two forms of harassment are recognized: quid pro quo, where submission to sexual demands is an explicit or implicit employment condition; and hostile work environment, where harassment unreasonably interferes with work performance and creates an intimidating, hostile or offensive working environment. Same-sex harassment (including that of men) was eventually recognized as a valid legal claim as well.