Kline's model went further than Kinsey's seven point scale because the factor of time was added. This suggests that an individual's attraction, behavior, fantasies, emotion, social, lifestyle and self identification could possibly change over time.
I find this fascinating that some people based on some factor the individual experiences in life could possibly affect the expression of their orientation. (And no don't flame me I'm not suggesting people change their orientation... I suggesting something that made have been hidden might surface) I think as we learn more about our selves and have new experiences or find out about new things our attraction, behavior, fantasies, emotions and self identification are shaped.
In my books I try to explore the spectrum of sexuality. I have two characters who happen to be demi-sexual (meaning in order to feel sexual attraction they need to have a bond with the person). One of them while he doesn't identify as bisexual could have found happiness with a woman or a man (though he had more inclination toward men) where the other didn't even decide if he were gay because he was so transfixed by his love interest he didn't feel the need to figure it out. Randy from Illusions & Dreams is probably trans-orientated (again if the attraction is based beyond sex I see nothing wrong with it... and I'll blog again about it some day). He wasn't even aware of his attraction to the duality in energy until he was exposed to people who were transgender. I have characters who knew they were kinky before they knew they were gay (yes I do think BDSM can be an orientation). Darius Stone in With Wings doesn't identifies as bisexual in the beginning of the book (ignoring some pretty obvious cues) but toward the end and into other books refuses to be told he's gay. It takes time but he adjusts his perception of himself to bisexual.
What I try to do in my books, on Facebook, in private chats with my Pretties is to explore sexuality. Labels are good (if we don't use them to pathogize) but labels need to be flexible. I bristle when I hear well that's not how X orientation is... yeah well that may not be how you express or experience X orientation or even how the people in your sphere experience/express X orientation but please don't invalidate someone who does experience in that way.
Under each stripe of the rainbow there's a glorious spectrum and I advocate for finding out more about yourself, your sexuality, your gender, your orientation so you can live a happy healthy life.
Wishing you many orgasms!