First date or family date!??

My partner doesn't know the difference of a first date, it's going to be our second date and she wants to bring her cousin and her little nephew, on our first date to the movies she brought her 2 best friends and her cousin. I just rolled with it, I just thought to my self (don't worry she won't do it again) but now she actually bringing her cousin and her best friend. I'm just like omg! I don't want to seem rude and say anything but... Idk someone please tell me what I should do