You don't need to prove it, the proof is the love you show to each other, but marriage is still a demonstration of your dedication to each other. The question is, if you truely love somone enough to want to spend the rest of your life with them, why not get married? Are you afraid of it, or are you in doubt as to how much you really love that person? You also have to rmebmer that people arn't all married by a 10 grand wedding ceremony, some like my parents jsut decided on the day, wen't to church, dragged a couple in from the street to witness it and got married. It's a matter of choice and somthing that should be agreed on by both parites. Not being married to your partner has the benefit of if it all goes tit's up, you have less legal problems to face, but to me, if that's a reason given to not get married, the purpose of marriage has been missed.