I have a dilemma - Birthday party or Quiz meet?

OK so. I have two things going on this Sunday, and I don’t know which to do.
The Birthday Party:
My brother’s fiance (I don’t know how to do the accent mark…sorry) turned 22 on the 12th. The party for her is this Sunday. I really wanted to go, because I have fun with her family and my brother.

The Quiz Meet:
I do this thing where churches put together teams and study a few books of the Bible and get together and have competitions to see who knows it better. I have a feeling this wouldn’t happen, but please don’t give me grief about doing quizzing because it’s Christian. Anyway, there’s a meeting this Sunday. Two of the other people on our team can’t be there, so we’ll be down to 4 people if I don’t go. That means if 2 of the people get out (by getting 5 questions right or 3 wrong), we’ll forfeit and the other team will immediately win. It’s not like we’re defending a winning season, though – we’ve won 3 out of 19 quizzes this year. So it wouldn’t change it that much if I was there or not.

My dad thinks I should go to the birthday party, my mom thinks I should go to the quiz meet. Any ideas?

P.S. Sorry about it being so long…