Some depressing story time that is happening to me as I type this

> My best school mate had a crush on the same girl as me.
> He didn't know that I had a crush on her too but we spoke about her upon his interest.
> He then asked her on a date and they were together for about three months.
> In January they broke up.
> He is still devastated but she is over him, however they are still great friends.
> I have always had great interest in her.
> Now that our last year of school is coming to an end I wanted to ask her out on a date on graduation night.
> The thing is, is the fact that she kind of showed interest in me while I didn't show obvious interest in her back in March.
> Now that graduation night is about 2 weeks away I want to make it clear to her that I want her.
> The thing that bothers me so much is this;
they are very good friends, if I ask her on a date she will say no and I will lose the both of them
If she says yeah then I will lose him (my best friend)
Right now I'm struggling to make up my mind whether to ask her on a date or nah, It's the only thing on my mind for the last week and a half. There is a huge chance of me being rejected but a slight one of her being with me...
What do I do.

(pic unrelated)