Why does he stop smiling and talking when he sees me and stares with a deep look?

When he sees me he either stops talking or smiling with the people he was and we stared into each other's eyes, like eyes quite 'wide' open and deep look?
We see each other every morning at the bus stop.
Updates
+1 y
Need your help please :)
Why does he stop smiling and talking when he sees me and stares with a deep look?
Post Opinion