Have a crush on my (maybe) straight friend

hey so I recently met a girl whilst travelling and we got really close, really quickly. So I don't know if that is why I've developed these feelings but yeah I can't seem to stop thinking about her, what it would be like if we were together. We also seem to have a crazy sexual tension/attraction for eachother, this much I can tell. And when we were last out she was very much initiating things which led to a lot of kissing. Anyways the problem is she has a bf, who I know she isn't too keen on, but that aside I'm curious if you'd think that this is normal if she was straight? If you're straight are you ever really attracted to the same sex/keen for initiating things or could it just be a phase? I'm bi btw but don't think she knows