A more thorough explanation:

Confarreatio was a type of marriage ceremony in ancient Rome that was used to wed members of the Patrician class. During this ceremony, the wife was brought into the husband's family and placed under his protection. This type of marriage was considered religious and involved the presence of at least ten witnesses and a high priest. The couple would sit side by side on a wooden seat made of an ox-yoke covered with the skin of a sheep that had been offered in sacrifice. A sacred cake made of Far was either tasted by or broken over the couple during the ceremony. Confarreatio was one of three ancient forms of marriage in Rome, but it fell out of use over time.