kiss him plain and simple :)
Just ask him , really nicely and talk to him and how u feel about this situation of him doing this and how it is affecting you .
she might feel threatened that hes friends with you. he might be embarrassed, scared, shy, felling awkward, who knows. you should ask him whats going on and hope he tells you what the problem is.
well its too bad for u .you said you are best friends but u really love him, i think he takes u as a best friend but not as a partner. i think u should tell him that you love him, before its too late. And when u say that, mean it, it might melt his heart.
There could be three reason he is acoiding you. First and most likely, He has a crazy crush on this girl and wants her to be his girlfriend. Therefore, he wants to show her that he is not taken by anyone including you. 2) She doesnt like you and has changed his opinion about you. 3) You could of made him mad.