Alright.
Emo is a brand of Punk rock in which the music is very slow, well thought out and made for people who whine all day about what's happening around them. Black Hair, heavy / thick glasses, lack of any enthusiasm is a symptom of Emo.
Metrosexual is something different. It's sort of like that SNL skit "The Effiminate Heterosexual." It's a straight guy who acts like a gay guy. Sort of like a Gay guy who's only into women.