Many of our current wedding "customs" originate from century old superstitions that would avoid incurring bad luck. In ancient times, marriages were considered a business arrangement made between family members, rather than a celebration of love. Marriages cemented alliances between families and insured transfer of land and wealth between them.

Often the groom had not met or even seen his future wife before the ceremony. The bride was kept hidden to eliminate any disapproval of her from the groom. It was feared that once seeing her he may have refused to proceed with the ceremony. This of course would have bought bad luck, by putting the family's financial arrangements in jeopardy. 

Today this custom has lost its relevance. Arranged marriages are not very common in our modern North American society nor will the Catholic Church condone a marriage between people who have never met. A Catholic wedding ceremony is a sacrament that couples administer to each other, so it must be a ceremony of mutual consent. Many couples are abandoning this custom of hiding from one another, choosing instead to have private time together for prayer and reflection before the ceremony. They then as a couple greet their guests upon their arrival.