Oh think not I am faithful to a vow by Edna St. Vincent Millay Lyrics

Oh, think not I am faithful to a vow!
Faithless am I save to love's self alone
Were you not lovely I would leave you now:
After the feet of beauty fly my own
Were you not still my hunger's rarest food
And water ever to my wildest thirst
I would desert you—think not but I would!
And seek another as I sought you first
But you are mobile as the veering air
And all your charms more changeful than the tide
Wherefore to be inconstant is no care:
I have but to continue at your side
So wanton, light and false, my love, are you
I am most faithless when I most am true