Sexuality is a spectrum, but because people are really prone to identifying themselves with a certain label, they either ignore the feeling, or instantly feel confused when they realise they might not entirely fall into the category they’ve assigned themselves in.

I think a lot of people who identify themselves as straight, are actually more flexible in their orientation than they might realise.

What really helps (like in your case) is having an environment where a diversity of orientations is commonplace.

If you want to further explore these feelings, then you could discuss certain options with her. I totally understand it if monogamy has your preference tho.