Harry is the second child for the Tauranga couple and was born just two days after older brother Emlyn's second birthday.
"We'll have to decide if we have joint parties or week apart parties to keep them special," Mr Bridges said.
Raising two boys would be "double trouble", he said.
"It's obviously going to make things busier but I'm pretty hopeful we can manage it."
The couple decided on Harry because they "thought it was a fun name".
"All the Harrys that are famous are full of life and fun so we thought that was good for this new guy," he said.
"He's going to have to be a bit of a character to protect himself against his older brother."
He shares the same middle name as Mr Bridges.
"The Prime Minister texted me. He's disappointed we didn't call him Harry John," he said.
Already the differences in the two boys were obvious, Mr Bridges said.
"Emlyn's got his mum's colouring and Harry is dark like his father.
Mr Bridges was non-committal about the prospect of further children.
"I think we're going to have to see how number two goes. If number three was a guaranteed girl, that might make the decision easier but I don't think that's how stats work. At this stage I'm keener than Nat is. Give her six months and we'll see," he said.