When we watched the Jimmy Kimmel Halloween joke (the morning after Halloween people recorded telling their kids that they had eaten all their kids' Halloween candy after the kid had gone to bed and all the kids bawled their eyes out) I turned to my husband and said, "I could never and would never do that to our kids!" It's cruel! The present thing wasn't quite as cruel, but I still thought it was mean and wouldn't do it. Admittedly, I laughed so hard I cried throughout the entire video clip of the kids. I would be so embarrassed by some of those kids' reactions that I would be mortified to let other people see them if I was their parent. "Tell him to suck my balls" had me gasping for breath I was laughing so hard, but I could not believe a child would speak like that and the parents weren't too ashamed to share it!
Kids take things too literally and are so sensitive that I would not play with their tender emotions like that. I wouldn't want someone to play a prank like that on me when I was a kid, and the Golden Rule is usually a good gauge for decisions. If I did do it, I would give them a real gift right afterwards.