Who do you love?

Both subject and object are a mystery. Does the PS refer to the object's initials? Or did the writer mean to say the magic words, but the moment passed, or maybe they just forgot? Was the idea for the object to open their curtains across the street and see this? And turn to their awakening lover and say: "well, that's all very nice - grand gesture n' all that, but why the hell did you graffiti the house over the road?" or... "I love you too"?