gender reveal party?

Maryna • Single mommy 🌈 rainbow baby amilia 11/20/16 ❤️ with another due 06/29/18 🤰❤️
I'm a new mommy and my sister wants to throw me a gender reveal party. but what do they do there exactly? are there games or is it just pop a balloon and it tells you the gender? can someone explain to me what else there is to do?