A make believe sexual orientation in which a person claims to be attracted to both sexes. Usually gay men who are afraid to come "all the way out" and seem to think being bisexual is more acceptable, or women, who participate in sexual relations with women to impress men and make up for a lack of self esteem caused by childhood sexual trauma.
"My wife is bisexual, we bring girls into the bedroom all the time!"
"John is totally bisexual, he bangs pussy all week. But Saturday and Sunday he lets dudes brick in his mouth..."