There's at least this something that you've done for you to merit this treatment from him. Try to recall.
Have you even tried to talk to him/her about this? I can't say I know what it feels but giving too much emotional investment over someone that doesn't pay you emotional dividends might be too costly.
I don't know if you have defined your relationship because you're not sure with the label you posted. Know where you stand and stand like a man.