Haven't we learned anything from horror movies? The creature is never really dead. It may be still for a little while, acting like it's dead, but it never is. Once you let your guard down it will revive to take its final victim before finally resting forever in hell. OK, so maybe that's all a little too serious for what happened in this photo, but the analogy is the same. Instead of being taken to hell with a demon, this girl was forced to actually kiss a fish. I don't know if it came back alive or if she just has butter fingers, but this made for a perfect fishy kiss.
If you're going to make some kind of joke like this, you better be ready for it to be true. Like if you pretend you're falling off a cliff, you better be prepared for the actual event of falling off the cliff.