[Drolefille]

OP, like most everyone else has said, no you don't have to party. How much or how little time you spend out at parties, or official events, or other orgs parties is all up to you. Your dues include a lot of those costs though so if you DO want to go out, those events are a good way to do it. If you don't, you'll have plenty of other ways to be social with your sisters, through non-partying events.