I used to work in retail for a company that rhymes with Fall Apart. I worked there close to four years and I'd made quite a few friends with co-workers. One of my friends worked in the Produce department and loved pulling pranks on people. Shortly after I moved into the Bakery, she had someone up there sneak a sticker onto my back that said "I need a hug". Fairly harmless prank, but I didn't know it was there until near the end of the day when the assistant manager walked past me while I was washing dishes and he said, "I need a hug". I turned around and stared at him like he'd lost his mind, and apparently that happens to be a comical look because he busted out laughing and told me the sticker was on my back.
Next day, the person who had sneaked the sticker onto my back told me that my friend in Produce had put him up to it. So next time she came back behind the counter on her way to Deli to get some plastic containers for sliced fruit, I pretended to smear icing on her back. She never trusted me walking behind her after that lol