What does it mean when a man calls you by your first, middle, and last name?

I am interested in this guy who always seems hot and cold. Recently we've been spending more time together in a large group of friends and has been addressing me using my whole name, i.e.,"Hey, Jane Doe Smith!" I often go by my first and middle name with friends I'm really close to and my name on my Facebook page is my full name. He tends to be a sarcastic guy, so I'm not sure if he's poking fun at me or trying to flirt.