heart-broken :(

yesterday, there have some argue between us. its dont always happen but yesterday its happen. what make me so sad is i begin to on9 at the time we argue, juz in 4ne. but i make my chat offline. what i observe is she chat with her friends so happily but when it comes to me its always look sad. i cant understand bot that. is she juz feel sad when she with me?so its a bad things to have me in her life rite?. . .which one u want me to be yours?bf or friend?