gild the lily

1. To adorn unnecessarily something that is already beautiful or perfect: “Morty had us all believing his tall tale until he couldn't resist gilding the lily.”

Idioms and Phrases

Add unnecessary adornment or supposed improvement. For example, Offering three different desserts after that elaborate meal would be gilding the lily. This expression is a condensation of Shakespeare's metaphor in King John (4:2): “To gild refined gold, to paint the lily ... is wasteful and ridiculous excess.” [c. 1800]