I like my best friends crush, who just happens to be my other best friend's boyfriend! HELP!?

Okay, well, my best friend (devon) likes this guy. She thinks he's the one. Over aim she is always talking about him to me. So I decided to meet him. At first I thought he was cool, just friend material. I knew that my other best friend (katie) was going out with him, so I thought it was weird to be caught in between this. But thing is, katie still had feelings for another guy the day she went out with this guy! I can tell devon is more committed to a relationship with him. now, she texts him ALL the time. i live near him so she's always over and we always hang out with him. we're losing katie as a friend because she's turning into an over-protective *****...i know it sounds like we're stealing the guy from her, but understand..lately he's been saying how he thought she'd be cool but she isnt. well. huge problem now. I started falling for him. and he likes me. only devon and i know that he likes me and i like him, but ever since she found out he's been weird to her and nonstop texting ME instead. i can't stand to see her like this. i want my friend back but i really like this guy. and she's really moody and weird and it's really confusing. one seconds she's like "take him!" and the next she says he is her property and to find another guy. it's all really confusing and i dont know what to do. he says he's breaking up with katie soon and she has no clue what's going on in between all of us. all she knows is that the guy and devon like each other. thats it. she doesnt know about me and him. i feel like im going insane. HELP!