When a member of the opposite sex acts so casual around you, you become fixated on having sex with them.
Girl 1: Dude, I'm dying to sleep with my boss. He is being so sexy casual with me.
Girl 2: Is he being sexy casual or does he just not care about you?
Girl 1: I can't tell. His sexy casual is masterful.
Girl 2: Ooh, good luck having sex with him.