When a male penguin returned home to find his wife cheating on him, he went on the attack.
A brutal National Geographic video shows the male arriving at his burrow, only to discover his partner shacked up with the homewrecker.
"He flips out. His strategy is simple: batter the homewrecker," the narrator says.
The fight is brutal as the penguins beat each other with their wings.
The battle becomes a stalemate, and the husband plaintively calls for his wife to come to him.
However, she refuses, and returns to her nest with her lover.
But the abandoned penguin refuses to let the mother of his children leave.
He rushes back in, and the fight turns bloody, as they try to gouge the other's eyes out with their beaks.
But the husband is unable to gain the advantage. In a final effort, he calls for his partner to join him again.
But she refuses. She's found a new mate, and the husband is left to watch as his wife leaves him for another.
Penguins are usually faithful to their partners.