What should I do?

So I'm basically stuck between a rock and a hard place!!  I just got invited to go to a sorority event! But I don't know if I should go or not...hmmm  I do love meeting new people and partying it up! But my mom says they are a waste of time and that I should only be focusing on my school work :(  

But what she doesn't know won't kill her ;) tehehehe