It means nothing really, unless additional words and actions are said and or done before, along with or followed up with being called hun. It could just be a girls way of calling people “dude” like a term of endearment.
This is a guy’s way of hitting on you! If a guy wants things to be a little more romantic, he’ll start calling you “honey” as a means to show you how he feels. Usually, when you are in a long term relationship, guys will switch from this pet name to another on the list.