my sister gave me a book many Christmas' ago,
"In Celebration of Mankind" I found it fascinating, the variation in the tradition of relationships around the world.There is a group of people in India who really had it worked out imho, a way of connecting a sense of responsiblility thru the whole community.
As for what is accepted and works in our western culture...it's just based upon a person's expectation and strength and preparedness to adapt.............and a whole lot of luck.
My personal case...We decided we had similar goals, we could achieve something together. We didn't feel the need to be married in the eyes of God or the law.
Ahhh and then( unlike what some ppl here assume, I read some veiled comments about lack of birth control) we planned to have children. That is where our desire to be married emerged. It just the felt right thing to do for the children.(I can't explain it beyond that)
The divorce statistics are alarming and I refuse to become one of them.Our marriage almost ended at one point. I think it was our wedding vows that helped us survive that...well they helped. ..a lot.So except for that hiccup( more like chronic indigestion for 4 months, followed by a large explosive *burp*) we have been together for 22years, married for 21, last July
so there ya go my humble opinion......is your sister younger?The scenario sounds familiar. My older sister( actually my whole family) waved me off with the muttered words
'it will never last" let them eat cake...wedding cake!!
to sum up? hhmmmm moi? basically nothing is wrong , nothing is right, it's all about individual committment and
Good Luck.