Sometimes yes, sometimes no. My oldest son asked me if she could move in with us when they got evicted for having a cat and about a year later, they decided to have a wedding. We had a big family engagement dinner to meet her family.
We became estranged when he left her four years later. He was subsequently was married to two other people I never met and he didn’t say much to me about it.
My youngest son married his first wife against my wishes, and I had to help him through a terrible divorce (and bankruptcy proceedings) a year later when she ran off with someone else.
He and his current wife were living with us for about a year when they surprised us by getting married just before Christmas. They thought it was a great joke to show us their marriage certificate the next day. They didn’t want a big fuss, and she was already six months pregnant.