Bisexuality has different meanings for different people.
In its simplest form, bisexuality is the attraction of a person to men and women. More complex forms may include attractions to transgendered people for example, a married woman makes love to her husband while he crossdresses as a woman or a lesbian is in a relationship with a male identified pre-operative female to male transsexual. More women than you think harbor bisexual feelings, dreams and fantasies. Many keep them at that level. Others express them through close emotional but non-sexual friendships.