Another Girl's Night... ?

It was only a couple of days ago that your girl had told you she was going on a girl's night with her instructor and a few friends; and now she's going out for another night with just her instructor? Well, you're happy she's found friends and seems to be feeling really good about herself, so what's the harm of it? Oh- she cancelled your date tonight so she could go out clubbing with her instructor? That's a little odd... no?