I'm not going to dinner with my aunt tomorrow
What is the reason why you are not going to go to dinner with your aunt tomorrow?
I want to see if I get a better invitation
You should not lie to your family members. You need to change your thinking and enjoy the time spent with your family. Your family will be angry at you if they feel you are mistreating them.
No one can stop me from going out there and having fun.
Just do not take spending time with your family for granted. If you would rather do something else than you should at least be honest with your aunt about it. Telling your aunt that you will not be there is the first step to this.