Wow is short for "are you serious?how dare you. I can't believe what I just witnessed. Someone kill me now please"
*A couple out on a date*
Girl:"I love this place,we should go here more often..."
Boy: *half listening* "yeah,yeah"
*Girl with a big butt walks by*
Boy: *watches her in amazement completely forgets he's out on a date with his girlfriend*
Boy: "what? What did I do now?"