Why does my male coworker avoid having to talk to me?

I have worked at a company for 4 years and this particular coworker has been there as long. If he needs to communicate with me, he only does so through email but will talk to everyone else about what he needs. It kinda hurts my feelings. I am nice to him, always friendly to everyone and he makes me feel like something is wrong with me. I used to catch him staring at me all the time but recently he just avoids me all together. What did I do to him that he treats me like I don't exist?
Why does my male coworker avoid having to talk to me?
Post Opinion