I'm going to ditch my girlfriend's family dinner to go study for a hard class
Can't you do both things?
No. I feel like I'd rather skip the dinner with them than hurt my GPA.
I see you have a conflict. Tell your girlfriend's family that you have to study and won't be able to attend the dinner. They should support you in your endeavor to do well in school.
Nah.
It's your choice in the end, I just thought it'd be nice to tell your girlfriend why you are skipping dinner is all.