Keep in mind that a lot of us guys are horrible at picking up cues. So trying to do subtle things may not be picked up by him.

There’s plenty of times I’ve found out later a woman was showing interest in me and I missed it.

All that being said. Smile and do the hair flip thing. Maybe he picks up maybe he doesn’t. Bring him some lunches now and then that you’ve cooked. There is some truth to the old saying. “The way to a man’s heart is his stomach”. If you don’t know how to cook there are plenty of recipes and videos online.