It was dad's turn by Thursday afternoon to carry the twins.
And proud papa, Simao, didn't shy away from his responsibility to carry the golden lion tamarin twins - on his back, on his front, on his side, and on his head - while the infants' mother, Rosie, took a break to exercise inside the Denver Zoo's Emerald Forest, hopping over her new family and swinging from branch to branch.
Nor was Simao, pronounced Su-mayo, bashful about showing off his 22-day-old offspring, which wrapped their primate hands and feet to his red fur and ruffled their way around their father's body, while occasionally staring through the glass window at dozens of zoo visitors who responded in kind.
The two monkeys went on public display this week.
It often took onlookers a few seconds Thursday to catch glimpses of the infants. But as soon as they spotted their pinkish faces protruding from their father's red and gold fur accompanied by their dark bulging eyes, the exhibit echoed with "cute."
Even brusque grown men couldn't help themselves from describing the monkeys as "cute."
"They're so cute, mom. They're this big," Zachary Griego, 8, told his mother, Victoria, as he widened his thumb and index finger to about 2 inches.
"They're itty-bitty. They're on (his) back. They're so cute," Isabel Vialpando, 6, told her mother, Brandy, who came to the zoo from Laramie.
"I haven't seen anything that small," Isabel's mother said.
The monkeys are an endangered species that live exclusively in the coastal forests of Brazil. About 1,000 remain in the wild. They get their name, the golden lion, because of the color of their fur and the coat and mane that form around their heads.
The last time golden lion tamarins gave birth at the Denver Zoo was in 2001. The twins are the first offspring for Simao and Rosie.
Names have not been given to the infants because zookeepers still are not sure of their genders.