Help with boy and friend trouble!?

I've been talking to this boy from my school on facebook and I think I'm really starting to like him as he is funny and we can have a laugh. I call him an aunty cause he's like an agony aunt, but then the other day I was talking to my friend and i said his name, then she was like who and i told her but didn't tell her i likeed him, next thing i knew she'd added him on facebook and got his msn addy and now shes always chatting and flirting with him and all because i said he was a laugh. I know some people might think I'm a bit jelous and i am, ill admit it but the thing is when she found out i liked another boy a few months ago she started dating him. I don't know what to do as i fell she's just going after the people I like as if to prove something.