I know straight guys like bi girls, but why are they so shallow about it and why are s hating me?

I'm a 18 year old girl and I never got much attention from guys in high school. I've only had one boyfriend in my entire life and I'm in the 12th grade now. Anyway, when I came out as bi and started publically making out with this other bi chick at my school, guys have gone nuts over me ever since. Now I'm dating this really hot guy I've been crushing on since middle school and I'm kind of falling in love. Before my feelings get too deep, how do I know that this guy is more mesmerized by my personality than my uality? Also, he loves seeing me flirt with other girls. The bi ones flirt back, but the actual s act like they're disgusted by me. Especially the butch ones. Why could this be?