Yeah, I've got a prank for you that's relevant to Valentine's Day.
There was this kid in high school, a genuine pseudo-intellectual with relationship problems. Sometimes, after he broke up with yet another girl, I would just tell him that it's okay, sometimes relationships don't work out. Now, before I go on, it's important to note that he thought he was smarter than me because... I don't know, I think it was a race issue given some of his other remarks at the time. So, whenever I told him anything, he would would say something along the lines of, "YOU don't understand, you're not smarter enough to understand MY problems".
I'm very tolerant of what others say, but one day, I got real sick of his behaviour, and I'll tell you why. You see, he met another girl and was talking about how great she was, but then started bragging about how he's not sure how to choose between this new girl and his "side chick". I wrote a note in his handwriting and snuck it to his new girlfriend's backpack saying to meet him under some tree in the courtyard during lunch, which is where he would go to make out with the side girl.
You should've seen them arguing like little chimps in a cage, it was hilarious. Then, in my next class with him, he was crying about the breakup and commenting on that note she found. Anyway, I went up to him and told him "it's all okay, maybe she wasn't the right one for you", only for him to tell me I'm too stupid to understand his problems again. Maybe I am too stupid to understand his problems, but I sure can get away with causing him more.
I don't think that's the kind of "prank" you're looking for, but I hope you enjoyed the story.
