Being bi-curious is not rare. Nearly everyone, at some point in their life, has curious feelings that don't correspond to their dominant sexual identity or orientation.
More About Bi-Curious
Research conducted by Eli Coleman in the 1980s found that while some people identify consistently as either gay or straight throughout their lives, many others rate themselves as bisexual, even while continuing gay or straight relationships. For many others, desires shift throughout their lives, suggesting that sexuality is a lot more fluid than we might imagine.
Women in particular may lean toward bi-curious feelings. A study released by Boise State University in 2011 found that of nearly 500 heterosexual women surveyed, 60 percent said they were sexually attracted to other women, and 45 percent had actually acted on those feelings and kissed another woman.