I'm going to leave my girlfriend to go to a group meeting even though she is crying
What makes you think that it is okay to leave while she is crying?
She is always crying and it hurts me.
I'm sorry you feel hurt. It would be more compassionate for you to stay with your girlfriend until she feels better, though.
I'm really hurt and need someone to talk to about it.
Maybe just stay there and try to talk to her about how it makes you feel too. Either way I think that it would be kind for you to take care of your girl while she is crying.