This little book contains fill-in-the-blank lines describing some aspect of your affection for your beloved. Just complete each line and voila, you have a uniquely personal gift your loved one will read again and again. Make it as mushy, racy, or witty as you choose! Need fill-in ideas? Read pointers on crafting the perfect Fill in the Love gift below. Knock Knock is an independent maker of clever gifts and books. Knock Knock's crackerjack in-house team creates products and develops books from the ground up as well as collaborating with outside authors, bloggers, and other creative types. Put the fun in functional with Knock Knock stuff.