He is flaunting this woman in front of my face trying to make me jealous!!!!?

I told this guy that I liked him a few weeks ago he had told me he was flattered but he wasn't sure since we were neighbors. Last weekend he had this woman over and she was walking like 4 feet behind him and later come to find out that he had told my friend that it was just his friend but yet he met up with some chick from a bar. He has called me honey and that is what has floored me since when I told him he needed to make up his mind on what he wants he suddenly writes me back a message that he is already with someone and writes it when she is there with him but yet he still wants to be my friend! Why would a guy do this?