Do men gauge romantic or sexual interest of a woman by staring at them or invading their personal space?

A coworker of mine recently held his blank cold stare when he walked past me even after I caught him looking. With other people he is usually more smiley and friendly. The same day he also leaned in so close to my face standing next to me when I tried to show him something that our faces almost touched.

Why would he do that? He never showed any interest in me. Could he do this to gauge my interest in him because of a suspicion that I like him?

Do men gauge romantic or sexual interest of a woman by staring at them or invading their personal space?
Post Opinion