Men, help me read eye contact.

Mainly interested in this guy who’s always extremely serious when looking at me: he holds eye contact and i’ve caught him looking at me when I can’t see him but whenever we interact he’s dead serious.

Never smiled back to me, he’s always nice though… He doesn’t seem shy but maybe I can’t tell cause he seems very masculine… I don’t understand if he’s just serious, or shy or intentionally doing that. He almost looks angry but I can tell he’s not haha