Has the combination 'fancy frogs' got any special connotation in English culture? The speaker says sometimes we wonder to ourselves what happens when a marriage's over and the 'fancy frogs' are stored away...
The only way I can make sense of this is if you mean the marriage ceremony, rather than the marriage. When the marriage celebrations are over, the "fancy frocks" might be stored away until the next such occasion.
You mention a speaker, so perhaps you misheard it.
not a teacher