Performing his hits on the program, the Grammy-winning singer gave Winfrey permission to spill the beans on the gender of the impending arrival.
Although Klum recently told Ellen DeGeneres that the couple didn’t know what they were having, Seal explained that Klum “can’t keep a secret” and had decided to let him share the sex of the baby publicly.
The pair announced the pregnancy last month, with the “Kiss from a Rose” crooner, 46, confirming the news onstage at Radio City Music Hall on April 16.
The Project Runway host, 35, and Seal were married in 2005. Together, they have two sons – Henry Günther, 3, and Johan Riley, 2 – and raise daughter Leni, 5, from Klum’s previous relationship with Flavio Briatore.