Why do guys act like they like you, then ignore when you flirt?

[broadlawyer179]

I'm in grade 10, highschool.

There's this guy who was in my class in the first semester of grade 10. He was always persistent in talking to me, always striking up conversations, even though i was shy and never carried the convo, he always tried to talk to me. In class, i would catch him lookin at me sometimes. In the hallways, he always looked at me everytime we passed by each other.
Second semester started, and he started a conversation with me on facebook. I barely see him at school since we don't have the same classes. Anyways, things were going great.. he was keeping the convo going and yeah! He also liked 2 of my selfies on facebook. This went on for a week until i decided to flirt with him.
I just gave him a compliment. He was like "I look like the grinch when I smile." I was like, "Nah you don't, your smile is cute!"
He saw that message 2 days ago on facebook, and hasnt replied since.

He's the awkward, dorky, nerdy type of guy.

So I'm confused. What are your thoughts?

[Abby]

Nervous or doesnt really like you