Why do some guys do this?

GemstoneCandy1810
Why do guys mumble when they talk to you? I had accidentally drop something on the floor when I was in school. And he was sitting next to me and he picked it up and gave it to me. I said "thank you" and he mumbled to me your welcome. And he's not the first guys that does. And that's not the only thing that guys do. Like why do some guys not look you in the eye?
Why do some guys do this?
8 Opinion