Probably because you're a mostly straight male.
Because she doesn't want you.
You seek that which you cannot have.
Keep jousting windmills, Don Quixote.
Because a lot of lesbians are hot and strong minded (that's sexy).
For some reason, a lot of guys I know are obsessed with lesbians. Something about the girl-on-girl action turns then on, I guess.
You probably want to have sex with her because she's a chick. Being a lesbian doesn't take out an X-chromosome.
is she a mostly lesbian? or a sometimes lesbian? Maybe her sometimes straight days could match up with your sometimes straight days and then sometime there'd be a day where you're both sometime straight. I just hope her sometime straight day isn't on your sometimes bi day because you might be busy that day.
You just want the ********* fantasy