Get a boyfriend, sorry I'm not very helpful
I have a friend who is bi but leans more towards girls (she is a girl). I'm a girl but I'm straight. She hugs me quite a lot, which I don't mind because we're friends, but it's getting a bit more than just hugging. I want her to stop, but I don't know how to tell her without upsetting her. What should I do?
It is perfectly fine to tell her that you don't feel comfortable. Just think about it, if a guy friend were to do the same to you, wouldn't you tell him to stop? The same goes with a girl, regardless of her sexual orientation. It doesn't necessarily mean that you think that she's coming on to you, it just means that you aren't comfortable with the way that she is touching you and that's okay.
If she thinks that you are accusing her of something, then just calmly say something along the lines of "I don't think that you intended to make me feel uncomfortable so I'm not accusing you of anything. I just wanted to let you know that I don't like being hugged like that." And if she were truly your friend, she'd understand that or at least try to. She may not agree with you but she'd at least try to be considerate and get on the same page with you.
And correct me if I'm wrong but I think that you feel this way because you don't want to come off as someone being against bi people, right? I personally don't like labels so I normally wouldn't identify myself as bi, but since I am attracted to both genders (although unlike your friend, I lean more towards guys) I will say that I'm bi just for this post. Anyway, as a bi person, if someone were to tell me to stop touching them in a certain way, I wouldn't feel offended about it because I understand that touching can be uncomfortable depending on the person and it's not necessarily a sign of their discomfort towards my sexual orientation. Of course I'd suspect that at first but as long as they don't outwardly accuse me of anything else, I'd be fine with it because I'm comfortable with who I am thus I'm not overly suspicious of others when it comes to this. I'm not saying that your friend will react the same way as I do but this is just some insight to let you know that she won't necessarily take this as a bad thing. Anyway, my point is don't treat people with different sexual orientations different from you. We are all human so treat us the same. Don't perceive your friend as someone special who can trespass your right to feel comfortable just because of her sexual orientation. But also remember to be civil about it because she is after all another human being.
Also remember that if she does happen to act badly about it and accuses you of being against her sexual orientation or whatever, then this girl is either not comfortable with herself yet (which is perfectly understandable if she does feel upset...accepting yourself can be hard, especially in a world where most people are straight) or she in fact did have feelings for you (in which case, I think that it's rather low that she's playing that card on you...no one should ever use their sexual orientation as a means to make someone else feel guilty about theirs and this applies to all sexual orientations. Although it is more commonly seen with straight people making non-straight people feel bad, the reverse can happen too). Yes you might lose a friend over this but if you had told her about what you felt in a proper and civil manner with no accusations or anything like that, then it's not your fault for making her feel upset.
Okay that's all I have to say regarding that. Hopefully it will all go well.