I would like to try it with her. We are really close and both of us is freaky but I don’t know if she would be up to something like that. I want to tell her but I don’t know how to. Please help this been happening for months.
There are a few things to consider here. First, are you and your boyfriend in an exclusive relationship? If you are, then he could consider you hooking up with anyone as cheating; even if you didn't tell him, you might feel guilty afterwards and that could mess your relationship up as well.
If we wanted to assume there was no boyfriend in the picture things could be easier. First, many people in their teens experience all sorts of urges - and these can often include feelings towards people of the same sex. This doesn't necessarily mean you're gay or bisexual, but it also could. Many people are quick to label themselves, when it can really take a few years to sort yourself out.
Generally, if you follow your heart and are honest with yourself, things work out.
As for your friend, do you have any idea if she feels the same way about you? Attraction is generally a two way street; when you're in a close friendship with someone, it's rare to find only one person really liking the other - the other person usually returns some feeling, on some level.
How close are you? Can you ask her about it? Or perhaps you're brave enough to just try to kiss her sometime?
If that all sounds too scary, you could always just have a general discussion about it. You know, 'So, what do you think of dating another girl? Messing around with her?' This can get you some of the answers you want without actually telling your friend you're interested in her sexually.
If you're close, your friendship should survive this even if she isn't interested....but be aware it might make things awkward for awhile.
Best of luck!