The secret is out — swimming legend Michael Phelps quietly married Nicole Johnson months ago and has kept it under wraps since, even while he was competing at the Olympics in Rio de Janeiro this summer.

They married in Paradise Valley, Ariz., where Phelps bought a posh $2.53 million home late last year. Its backyard faces Camelback Mountain.

The couple has never publicly acknowledged that they are married, but their record of marriage shows they were wed June 13, both at the age of 30. Phelps' agent, Peter Carlisle, officiated the ceremony, according to the record.

Johnson posted an Instagram photo on their wedding day, June 13, of her, Phelps and their infant son, Boomer Robert Phelps, standing by a pool at night wearing casual clothes, captioned "Such a memorable night with my lil fambam."

TMZ Sports broke the story Wednesday afternoon. Attempts by The Arizona Republic to reach Phelps' agent were unsuccessful.