@Thiron not all obligations are either legal or financial. There are social obligations too. It's something less prevalent in your average western family, but even then it still happens in more conservative families. And it's not that uncommon in eastern countries.
You basically don't want to get disowned by your family for disobeying to your parents, even if it wouldn't impact you financially or if they can't legally force you to obey.
I'm about tired of this whole "he is everybody! and nobody is worthy enough to date shit" because baby let me tell you something if he fine, he gonna be mine. It's in the Bible.
@semicharmed there are actually marriage registrations form in some wedding magazines, most especially if they are "special editions" where they are designed.