A wooo girl is a girl, or usually a group of girls, who hang out in bars and put their hands in the air and scream wooo whenever a song they like plays, a drink is served, or another friend enters the room.
If a classic song is played in the bar, all wooo girls will raise up one arm fully extended and scream wooo at the top of their lungs.
The Woohoo Dance is a comical dance a guy does for his partner while naked. The Woohoo Dance is performed by quickly twisting one's hips to and fro while shouting "Wooo Hooo" very loudly. The dance is performed properly when the penis effectively generates a loud slapping sound against the legs.
I was seriously pissed at Joe last night, but his Woohoo Dance brought me out of it as usual.