Not gay or bisexual, but in between bi and straight. Like, being straight, but you would consider doing something with a member of the same gender should the situation arise. Mainly for pleasure and adventurous reasons, you probably wouldn't date them. Also can be called bent.
It DOESNT mean gay as some people would say it does.
I didn't think sarah was hetero-flexible until she gave me a lap dance and then went off to make out with her boyfriend.