I've noticed if I talk to this guy I like I tilt my head and smile a lot at him. He usually tilts his head too when we are talking. If I greet him and I smile he tilts his head and smiles back at me.
I obviously don't think if a guy tilts his head when looking at a girl that he's in love or anything lol. Just that he is interested in what she has to say and is open to her. Am I right?