Accused lesbian

Today I was talking to my guy best friend and something came up and I found out that he thought I was a lesbian. He has still been my best friend and always talked to me and kept my secrets I am not that mad at him(to be honest I thought he was gay). But he thought I had a crush on one of my friends, she heard about it and we walk home together everyday yet today she walked with different people she walked straight past me and ignored me and in class she ignored me again. i have no idea what to do do I pretend nothing happens do I cut her off do I explain to her..??? I have no idea. She is a very I think I'm better than everyone else person so she would proberly believe it. 
Ps:I am not a lezzo