pillow, as it is centered on a "fat Quarter": http://www.spoonflower.com/designs/1519507
This is a manipulated detail of a photo taken of the bridge behind Notre Dame in Paris. Couples pledge their love by placing a lock on Paris and other European cities and throwing the key in the river. You also see combination locks, but I think if the couple is really committed they should use a device with a key and throw it in the water!