I think some of the comments here about homophobia and biphobia are more applicable to men than women and that, in some ways, it is the opposite for women. Yes, bi men are assumed to be really gay and male bisexuality isn't viewed by many people as being real - but, with women, we are assumed to be sexually fluid or at least a bit bi - A woman leaving an opposite sex marriage for a woman is assumed to be bi, a man leaving his wife for a man is assumed to be gay. Even if you have only ever dated the same sex (as I have), there is still this idea that women are sexually fluid and that you are either lying or not being open-minded - not helped by some bi women identifying as lesbians - possibly because they don't believe women can be exclusively same sex attracted so just think it's about choosing to date a woman?

I also think there are some stereotypes about and dislike of lesbians which are lesbian specific - some straight woman are okay with bi women or a woman who always dated men "but just happened to fall in love with a woman" but have a lot of negative perceptions about lesbians. I think bi women face stereotypes and negative perceptions too but they are different.