Ah, young love. Harry's first crush is Cho Chang and, in this movie, he finally gets to lock lips with her. Their first kiss is about as adorable as you would imagine:
CHO CHANG: You're a really good teacher, Harry. I've never been able to stun anything before… Mistletoe.
HARRY POTTER: Probably full of Nargles though.
CHO CHANG: What are Nargles?
HARRY POTTER: No idea.
Their love story doesn't turn out so happily-ever-after though. There's a lot of weirdness around the fact that Cho was dating Cedric in the last movie … and Harry just happened to see him get murdered. Awkward. Plus, Cho's the one who reveals the location of the Room of Requirement to Professor Umbridge. Say it ain't so, Cho.
Of course, Harry finds out later, it's not really Cho's fault. Turns out that Cho only ratted out Dumbledore's Army because Umbridge slipped her some Veritaserum. She didn't mean to tell. It was the potion talking.
Cho kinds of works in this movie as a stepping stone. She's Harry's first love, but she's also pushed aside when the plot needs a fall girl. We wonder who will step into her shoes as the romantic interest in the next movie? Hmmm… maybe a certain red-haired witch?