You kinda have a crush or thing for him, and it's understandable with the mild flirtation thing.
If I were you I would let it be for now...the ball is in his court.
(And I had to deal with a friend's crazy ex-girlfriend before, trust me you don't want to deal with that!
And we were just friends...but she would follow us and sit outside my house!
Then she would call me and tell me she that followed us, and followed him driving me home, and knew where I live and I had better leave her boyfriend alone (there was not even anything going on there - just friends)...
oh yeah she had recently just gotten out of a mental ward!!!!
Felt like I was living a Stephen King novel!)
I am just saying....don't underestimate how crazy, crazy can be!