As a lifelong supporter and former chairman of Watford Football Club, Elton John is very clear which team his son will support.
"If he chooses Chelsea, I'm going to kill him," joked the pop star in an interview with the Daily Telegraph.
In fact, Zachary – who was born to a surrogate mother in LA on Christmas Day – already has his own Watford strip waiting for him at home in London.
And the proud dad says he's already looking forward to taking him to matches later on.
For the moment, father and son bonding revolves around nappy changing and bed time.
Elton and his partner David Furnish take it in turn to read their baby a story at 6.30 pm each evening.