I HAVE A PROBLEM!?!?!?

Hey there! Mmkay. So my best friend who I've known since I was 3 has a crush on my best guy friend who I've secretly had a crush on him for about 2 months. I did'nt tell her I had a crush on him because it would be kinda weird for us liking the same guy. Anyways she's been too shy to actually start a convorsation with him or talk to him. At first I thought he just liked me as a friend but now I pretty sure he "likes" me. He stares at me durring cl, asks to be my partner for projects, talks and what it seems like flirts with me alot, and tries to be funny when I'm around..and he doesn't do that to any other girl even if they are friends. Actually he can be really shy around other people but not me. Anyways I like him back but the problem is my best friend likes him. She would probably be cool if we went out(or say she is) because she didn'nt have a major crush on him and I saw him first. But she gets jealous about this stuff easily even if she doesnt admit it. SO i don't know what to do because I don't want to hurt our friendship but I can't stop liking him....help! and thanks bunches<3