This practical joke comes in two different varieties but applies the same principle. You either need to get your victim to smell or put their hand over a food item, and then you shove their body part or the food item to precipitate contact between the two. The objective, either way, is to make a mess that will be smeared on the person’s body part(s).
For instance, you may be eating a birthday cake with some friends and you say to one of them with a curious inquisitive expression, “this cake is delicious but the icing sort of smells like fried bananas”. This will no doubt get the person to wonder how in the world the dessert could smell like bananas when it’s a white vanilla cake with chocolate icing and they will lean in to take a whiff for themselves. Now is your chance to strike! Smack the bottom of the plastic plate with full force, so the cake and frosting smear on their nose and face. Trust me its funny and you can get tons of people with tons of different foods. I kept getting the same people multiple times until they started to catch on and eventually played the same prank on me.
If you want to keep it clean then you can just tell the person to smell anything that won’t make a mess but still shove it in their face. I love saying something like, “That newspaper made my hands smell like paint” and when they go to see if their hands smell too, then shoving their hand in their face.
The other form of this gag involves luring someone to put their hand over a runny or gooey food and then slamming their hand down into the food. A phrase along the lines of “feel the heat coming off of this applesauce” usually does the trick. It’s so simple yet so fun.
This joke works particularly well with a group of school children. The reason is not only do you get pleasure from smacking one child’s hand into their pudding and seeing the reaction on their face, you get to see a whole room full of children falling for the prank. This is because it starts a chain reaction where each child pulls the gag on their friends. You just sit back and watch the evil that you created pass from child to child. For many, you may be introducing them to their first practical joke they ever play.
Although I have never tried it, I have conceived of using the “feel the heat” joke to play a terrible prank on someone. If you had some clear superglue (preferably the quick dry on contact type) smeared on a table or desk you might be able to superglue the person’s hand to the table. Due to the impending emergency room visit, this probably isn’t a very good idea but it sure is funny to think about!