Yay partysss!!! Both of my best friends birthDAYS are this month but both of their birthday PARTIES are on the same day , One is a quinceneria and the other is just a regular sleepover but they both start at the same time.
Well what everyone so far has had a good answer. Seeing as the other is a sleepover and not just a party with a set start and finish, you can do both. Go to the Quincenceria for a few hours or so and be with that friend and then head over to the other party. Both of your friends are important and if you are able to go to both of their parties than tell them that you have to parties to go to so they understand your situation. You should be able to go to them both.