People buy wedding cakes for handfastings, renewals of wedding vows, and many other kinds of ceremonies somewhat like a wedding but not legally a wedding, such as the sham weddings that people hold after being married by a justice of the peace at a courthouse. People even buy them to use on stage during theater productions.

That's not actually at issue in the Colorado case. "I will not sell you that cake because you're gay" is the issue, not the type of cake.