An Exercise in Impromptu

My love, she asks of me a verse
And how could I but acquiesce
But this gesture I cannot rehearse;
For words can't tell her loveliness

A lyric cannot tell of things
That chase the vision of her smile
My lips are sealed, but my heart will sing
And leave me breathless all the while

I'm truly at a loss of words
So what on earth am I to do?
These sentiments must go unheard
By sweet, indescribable you.