We actually don't unless you declare your relationship a civil partnership. Co-habit gives you no rights what so ever, unless you've got both names signed on documentation, such as tenancy papers or mortgage.Danzaivar said:By the way, I'm not sure if the US has this or not but in the UK if you co-habit with someone for over 3 or 5 years there are laws against you being able to "Just change the locks on your door, and its over."...
OT: I think marriage in the sense of the big wedding and all the guests is overrated. I personally wouldn't get married, unless I was in a long-term, stable relationship and my partner suggested it, to simplify tax benefits and the like. Also the marriage would take place after some sort of pre-nup was made.
Even then, I would't pay hundreds/thousands on a big celebration. Probably, a meal with some guests, kinda like my mum and dad. (They spent around £100, taking into account inflation, total on their wedding 25 years ago)