By MAGGIE WICKS
They live together, flirt together and provide for each other.
They've been a couple for 10 years and it's just like any loving relationship - they've even tried to raise a family together.
What makes this partnership so special, however, is that the lovers are King penguins - and both are male.
Julio and Fabio (known as Fatboy to his friends) are 16 years old and live at Kelly Tarlton's aquarium in Auckland.
The couple have been together ever since they came to Kelly Tarlton's from San Diego in 1994.
Bird curator Rochelle Deane says King penguins are usually quite promiscuous, but Julio and Fatboy are an exclusive couple.
They may flirt with the other males a little - Julio tends to get quite jealous of Fatboy's gregarious nature - but they have remained faithful for a decade.
"Fatboy and Julio have never shown any interest in females," Rochelle says. "They have eyes only for each other."
The two spend their days swimming and playing together. They trumpet and bow and regurgitate food for each other, just like the straight couples.
"They don't actually bonk," says Rochelle. "But they're totally out there."
Six years ago they even attempted to start a family when they were given another couple's egg to care for.
The egg turned out to be infertile, but Rochelle says she wouldn't hesitate to give them another.
King penguins are the second-largest penguin species. They can live for up to 22 years and grow up to 1m tall.
Fatboy is the heavyweight of the Kelly Kings, at 22kg.
Kings don't establish nests. Instead they incubate their eggs by balancing them on one foot to keep them warm. Both parents help to raise chicks.
Kelly Tarlton's has 29 Kings and 58 Gentoos - the world's third-smallest species of penguin.