He likes you, a lot of people use that to cover it up or sometimes they can't talk. I like this one guy and I am never able to get even hey out of my mouth and I love him sooo much. I can't get over him no matter what.
If he ignores you just ignore him too. He isn't really nice to do that then. Or he might like you back and is shy around you so he ignores you to keep that inside
Get your flirt on girl! Like don't over do but make it perfect. Maybe you could tell a joke