Flirting I think

I’m 17 (F) nearly 18 - not that that matters I’m just prefacing.
I’ve been working at my workplace for the past year and there’s a guy at work who at current , has my eye.
Is this just because I’m bored? I don’t know .
Is it because he works with me ? I don’t know
Is he flirting with me? Answer remains unclear as of right now.

so I’m quite a sarcastic person , and I’m also quite awkward at work sometimes - imagine that Natalie Portman meme.
So I was doing an intensive scheme, when the bantering began.
He would laugh and shake his head at me whilst I am undeniably dying of embarrassment doing what I do.
Whatever.
And we worked together for 8 days in a row. (He gave me a cookie too so defo swayed me the right way)

What has me questioning is the fact that he’s started calling me stupid/ an idiot , etc. (And on personal experience, guys calling me stupid has equalled flirting)
Banter and bullying (in good spirits) is a big part of flirting for me cause it’s funny I fear. OBVIOUSLY it can’t all be bullying though there has to be some niceness there.
so he’s asked hypotheticals , asked about what I’m planning to do for uni, asked about my current education, all that stuff , too, it’s not just a silly little being rude and leaving it there.

Anyway.
At the end of summer he goes back to school, and he’s currently on holiday. The funny thing is he goes to school 4 hours away, and basically only works during the holidays.
Last time I saw him he asked when I’d be working again and told me he’d be back near the end of August, and then would be gone back to school. A part of that makes me feel a little upset considering I think I do have a little crush on him. Yes I’ll see him at work , but what about when he goes back to school?
And what if I don’t see him at work again? Do I have to wait until next year to see the guy?
And if I do see him again , do I ask for social media?