One woman short of being gay is a term that closeted gay male husbands say to their straight wives so they can stay in a marriage of convenience.
Or sometimes the straight wives will tell this to everyone else about their marriage to deny that they are married to a closeted gay man who wants nothing but a marriage of convenience for appearance sake to appear "straight".
Belle is married to Bill and Bill is a closeted gay man, Belle likes to tell everyone that Bill is one woman short of being gay because he's in a marriage of convenience with him.
Bi-gay means that someone is bisexual but they are more into the same gender for sexual attraction and romance/relationships. Women who are like this are called bi-dykes or bykes.
John is a bi-gay man in that he prefers men for sex and relationships and he's just into sex/casual dating with women but he's not gay/homosexual since he's sexually attracted to women.
Heteroflexible is just another term for being bisexual that people who are closeted about their sexuality and want to hold onto some part of a heterosexual identity that never was there in the first place since they are not straight or hetero at all.
If the person was really heterosexual or straight they would not be having sex with the same gender while drunk or at all, or sexually attracted to both genders or bisexual.
I'm heteroflexible it means I'm bisexual but I can call myself by a different label to avoid the biphobia that gay men and lesbians have towards bisexuals.