Heads or tails.

I was just getting started in a new relationship with one of my sister's co workers. This thing started out slow, with a lot of going out, talking, getting to know each other before we got into sex. I'm a pretty open-minded guy when it comes to sex, but this babe has kinda thrown me for a loop. She tells me that she is bisexual. And she has a girlfriend. My first thoughts were: three-way? But she made it clear that her girlfriend was only into women, knew about me, and wanted me out of the way. So what does this mean? I ask. Call me in a couple of weeks, she says. And we'll see. So I've been tossed aside for another woman? What
a fucking creepy-ass feeling. The sex we had was hot. But knowing absolutely nothing about lesbian sex, how the hell can I compare it with the hot sex she's getting from another woman? I told my sister, who said,"No shit?" and then laughed her ass off. She told me to forget about this babe. Find someone else. But I'm kinda stuck on this girl. And I was willing to share her with her girlfriend. It's like depending to win a flip of a coin. Sounds fucked up I know, but I think I will call her in a couple of weeks. Does this seem normal?