Tradition says:
During the cake cutting ceremony at a wedding reception there was usually a decorated
knife that the bride used to cut the first two slices of cake symbolizing the traditional role of wife as food preparer.
The groom feeds the first bite to his wife, symbolizing the traditional male role of provider. The groom often places his hand over the bride's for cutting the first slice - and for the photos.
While there is a basis for these traditions, it is not strong enough to cause problems in today's society where the two roles have blended.
The cake's top layer can be frozen to be served on the first anniversary (many couples till follow freezing the top tier tradition).
"Professional Development Program" by the Association of Bridal Consultants.