More Neighbour

So my conversation with the Neighbour actually continued after my post. I thought it was over, I thought I managed to cut it short. But when I posted other pics I got more messages from him. He complimented me on the other pics and mentioned my Instagram... That's when I took the opportunity to call him a born hacker. 

He actually apologised for being invasive. He admitted to having looked up all our neighbours too. He also realized that it was his gf who had told me, he said 'looks like I've got a spy in the house'. As if he didn't know his gf and I were talking. ...Weird. 

Anyhow I still don't know what my opinion of him is. I can't really understand if it's friendly harmless flirting or if I should be very wary of this guy.