Families & Friends of Gays & Lesbians Support Group
This community is dedicated to parents, siblings, grandparents, other relatives and friends of someone who is either gay, lesbian, bisexual, transgender or questioning their sexual orientation. The purpose of this community is to help families and friendships grow and maintain positive relationships with gay sons, daughters, family or friends.
There is such a thing as bisexuality. It is not picking whoever is handy at the moment (though there are some people who use the label bi as an excuse to have sex with anyone).
Think of it as a spectrum. It's actually called the Kinsey scale. It goes from 0-6, 0 being 100% heterosexual, 6 being 100% homosexual. Not everyone can score an exact 0 or 6. A lot of us fall somewhere in the middle.
Most bisexuals have a 'preference' (I use that term loosely) meaning that even though they may be attrached to men and women, they tend to date one gender or the other. I have an ex who is bi, but dates lesbians 90% of the time.
In terms of your daughter, as long as she is looking for an honest relationship with the guy, don't worry too much about it. She is following her emotions and that's not a bad thing.
Good luck,
Owl