The word that describes my spring break so far is... Abandonment! Help!!

So.... I've heard this saying... "Chicks before Dicks." It refers to a girl that is supposed to think of her girl friends before her boyfriends. And I think everyone should call it a rule, not just a saying. Because my best friend hangs out with her boyfriend about 24/7. Her parents let him stay the night at her house and his parents let her stay the night at his house.

First of all... I really don't like her boyfriend (AKA C). C is really immature and thinks he is emo. I hate fake emos. C is a freshman. He's not even all that great looking. He brings my friend (lets call her K) to depression all the time, by guilt tripping her. He makes her so much more moodier than she used to be! K has changed sooo much since she started dating C.

*We used to dance down the street and act like we didn't care about the world
>now she complains about "what if he moves and I never see him again" or "I don't want to dance, I'm too depressed"

*She used to be loud and confident...
>now she's quiet and reserved. She cries often about him. She would rather watch a movie than go swimming.

I'm getting really tired of all of this... After 4 months of this I don't know what to say to her. I've tried telling her that her world should not revolve around C! that I think she has changed. And then when I tell her she says "Oh, well I'll try to be more like myself" and it works for an hour. then she's depressed again.

GRRRR I just want to shove C off a bridge that overlooks concrete!!!!