Brian Austin Green Dishes on Son's Secret Birth

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Megan Fox and Brian Austin Green welcomed their first child together in September, weeks before the public was any the wiser. But how did they pull it off?

Turns out the arrival of their son Noah Shannon occurred just as fellow celebrity parents, Reese Witherspoon and Jim Toth welcomed Tennessee James on September 27.

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"I've been wanting to send Reese Witherspoon flowers for, like, a month and a half now," said a grateful Green, who was delighted at the paparazzi distraction.

The 39-year-old star told Ryan Seacrest on his radio show Tuesday that he and his bride of two years rode out the anonymity for as long as they could.

"We got out of the hospital and nobody knew," revealed Green. "We got home and thought, 'This is unbelievable.' We weren't expecting to be able to get away with it. We were expecting all the [media] guys in the hallways and the parking structure."

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As for tackling daddyhood for a second time on the eve of his forties, Green was admittedly a bit rusty getting back into the business of babies.

"I've never felt so 40 in my life," he joked. "You get about three hours and then he'll fuss about something. First you spend 10 minutes figuring out where you are, then you realize, 'I'm home and it’s my child.' Then you figure out what's wrong — a diaper or hungry."