Since it's on the back, I'd just applique a heart or flower or something over it. My very first quilt was destroyed by an anxious Great Dane puppy left alone, nesting through quilt, blanket, sheets, electric mattress pad, and just stopping short of mattress. I came home to a soundly sleeping dog and a huge debris field. A little character mark is not going to hurt the wearability, and give it a little more personality.