Shakespeare's Sonnet 102

My love is strengthen’d, though more weak in seeming;I love not less, though less the show appear;That love is merchandiz’d, whose rich esteeming,The owner’s tongue doth publish every where.Our love was new, and then but in the spring,When I was wont to greet it with my lays;As Philomel in summer’s front doth sing,And stops her pipe in growth of riper days:Not that the summer is less pleasant nowThan when her mournful hymns did hush the night,But that wild music burthens every bough,And sweets grown common lose their dear delight.Therefore like her, I sometime hold my tongue:Because I would not dull you with my song.

My love has grown stronger, though it seems weaker. I do not love less, though I show it less. Love becomes a product for sale when its owner announces its great value everywhere.
Our love was new, only in its springtime, when I used to celebrate it with my poems, just as Philomel sings at the start of summer and falls silent as the season matures. It is not that summer is less pleasant now than when her mournful songs hushed the night, but that birdsong fills every branch, and sweet things lose their special delight when they become common.
So, like her, I sometimes keep quiet, because I do not want to bore you with my song.