It is possible to accidentally superglue your tongue to itself.
It's not permanent, and it's certainly not fun, but it's possible.
Did you witness this? Or did you experience it yourself? This is too funny.
I did it to myself - I was making a batch of badges to sell ("pins" for our colonial cousins). Superglue works by reacting with traces of water that are usually found on the surfaces of almost all substances, but when you're gluing stainless steel to wood, the wood soaks up the glue before it gets a chance to react with the water on the metal.
Solution: lick the the steel pin before dropping it onto the drop of glue soaking into the wood. Works well.
Unfortunately, I had dropped the bottle of glue, and it had sprinkled droplets of glue all over the pile of yet-to-be used pins.
I picked one up, didn't think to check it for the presence of glue, and hilarity ensued.
Well, the rest of the family found it amusing, but I had a lisp for hours...