I'm a girl and I'm bisexual and I'm in love with my best friend who is also girl and have a boyfriend. But from the first day of school( this year is my first year in this school) she asked me go out with her to buy some clothes when we didn't really much talk together and day by day we were closer and hug very tight and always sit next to each other and when she's sad or have pain in her boddy like period pain, she hug me too long until the break time ends, and every one else think maybe we are together because of this things( the way they look at us). . I am always there whenever she would need a shoulder to lean or cry on.We are so close.
But she always say that how much she like her boyfriend and how sweet he is but in the other side she say to me your stronger than him( because when she hold my hand and I carry her hand she thinks I can do it better than her bf) and also she says I have soft hands and skin like her boyfriend and she always say things that I'm like her boyfriend or better than him...
Do you think she likes me too and do I have any chances to be with her?
And by the way she sent me about things like masturbate or lesbian jokes...

We could all guess but we can't really give you the answer you need. Since she's such a close friend, I recommend you address this directly and candidly with her and set some boundaries.

How about something like this:

"you know I'm bisexual, right? Because of that, when I have a close friendship with either a girl or a guy it can be confusing sometimes, and it's confusing with you. Since you have a boyfriend, I assume we're friends. But sometimes, you seem to be in a lot of physical contact with me - kind of flirtacious with the hugs and all of that, more than what's typical in a relationship between two straight girls. So, I guess I'm asking you where you're at with things. Are you bi or lesbian, too? Do you just think of me as a friend, or are you testing the waters with me?"

If she's interested in you romantically, you should draw a boundary and tell her, "well, we can date but only if and when you are free to date. You have a boyfriend and I don't want to disrespect anyone like that, and I don't want to deal with knowing the girl I'm seeing has a boyfriend - it's too much."

See what she has to say.

She already knows you're bi, so it's not like you're letting the cat out of the bag. And I don't think you have to pour your heart out. If you raise the issue, she'll know that you're open to dating her, which is enough for now.

How old are the parties involved?