A National Geographic documentary has filmed the moment a penguin returned home to find his wife with another man.
What followed is one of the most savage and depressing encounters ever featured in a nature programme.
Confronted with the choice between her old partner and the new flame she rejects the returning husband.
So he fights for her. And what a fight.
Predictably, people are a little shaken by the video.
If you too are traumatised, here’s some positive penguin news.