I'm not a guy, but for me it wasn't anything formal like that. I met my boyfriend's mom about a week after we kinda started dating, when I went over to their new house to help them paint the rooms.

I met his dad around the same time, because we were hanging out at his dad's house (his parents had just finalized their divorce), and I met his sister a couple months after that. I met his uncle and aunt at Christmas dinner, about seven months after we started dating.